dissertation on bullying

Do a more advanced search »

Search for dissertations about: "bullying"

Showing result 1 - 5 of 48 swedish dissertations containing the word bullying .

1. Students’ Perspectives on Bullying

Author : Camilla Forsberg ; Robert Thornberg ; Marcus Samuelsson ; Gunnel Colnerud ; Christina Osbeck ; Linköpings universitet ; [] Keywords : SAMHÄLLSVETENSKAP ; SOCIAL SCIENCES ; SAMHÄLLSVETENSKAP ; SOCIAL SCIENCES ; SAMHÄLLSVETENSKAP ; SOCIAL SCIENCES ; bullying ; students’ perspectives ; interviews ; bystander reactions ; grounded theory ; symbolic interactionism ; mobbning ; elevers perspektiv ; intervju ; grundad teori ; symbolisk interaktionism ;

Abstract : The aim of the present thesis was to listen to, examine and conceptualise students’ perspectives on bullying. Students’ perspectives have not been commonly heard in research and less qualitative research has been conducted. READ MORE

2. Bullying and social objectives : A study of prerequisites for success in Swedish schools

Author : Björn Ahlström ; Jonas Höög ; Roine Johansson ; Umeå universitet ; [] Keywords : SAMHÄLLSVETENSKAP ; SOCIAL SCIENCES ; Successful schools ; Social objectives ; Leadership ; Bullying ; Insulting behaviour ; Sociology ; Sociologi ; sociologi ; Sociology ;

Abstract : This thesis examines the relationship between organizations structure, culture and leadership. The specific organization that has been studied is Swedish secondary schools. The Swedish schools have a divided task, first to develop the students academic skills and secondly to develop the students socially and civically. READ MORE

3. Social stressors and their association with psychosomatic problems among adolescents : Implications for school social work

Author : Victoria Lönnfjord ; Curt Hagquist ; Daniel Bergh ; Mona Sundh ; Patrik Karlsson ; Karlstads universitet ; [] Keywords : SAMHÄLLSVETENSKAP ; SOCIAL SCIENCES ; Social stressors ; adolescents ; psychosomatic problems ; school social work ; parental unemployment ; family residency ; schoolwork pressure ; academic achievement expectation ; bullying ; bullying victimization ; bullying intervention ; self-efficacy ; disability ; long-term illness ; Sociala påfrestningar ; ungdomar ; psykosomatiska besvär ; skolsocialt arbete ; föräldrars arbetslöshet ; boendesituation ; press i skolan ; krav på skolprestationer ; mobbning ; utsatthet för mobbning ; interventioner mot mobbning ; tilltro till sin egen förmåga ; funktionsnedsättning ; långvarig sjukdom ; Socialt arbete ; Social Work ;

Abstract : The overall aim was to investigate associations between family-, school- and individual-related social stressors and adolescents’ psychosomatic problems, and which factors might moderate these associations. A cross-sectional study design was employed to collect data and 3764 Swedish adolescents (girls 51. READ MORE

4. The Everyday Practice of School Bullying : Children's participation in peer group activities and school-based anti-bullying initiatives

Author : Johanna Svahn ; Ann-Carita Evaldsson ; Marie Karlsson ; Susan Danby ; Uppsala universitet ; [] Keywords : SAMHÄLLSVETENSKAP ; SOCIAL SCIENCES ; School bullying ; children?s participation ; peer group interaction ; classroom interaction ; interactional practices ; morality-in-interaction ; ethnography ; ethnomethodology ;

Abstract : This thesis explores the everyday practice of school bullying by examining children's participation in peer group activities as well as in school-based anti-bullying activities within an educational setting. The empirical material is drawn from a long-term (1 year) ethnographic study conducted among preadolescent children in a 5th grade class in a Swedish elementary school. READ MORE

5. School Bullying and Power Relations in Vietnam

Author : Paul Horton ; Helle Rydstrøm ; Jeffery Hearn ; Neil Duncan ; Linköpings universitet ; [] Keywords : Bullying ; power ; Vietnam ; school ; education ; gender ; ethnography ; surveillance ; normalisation ; control ; discipline ; teachers ; students ; silence. ; Mobbning ; makt ; Vietnam ; skola ; utbildning ; genus ; etnografi ; övervakning ; normalisering ; kontroll ; disciplin ; lärare ; elever ; tystnad. ; SOCIAL SCIENCES ; SAMHÄLLSVETENSKAP ;

Abstract : Taking seriously the oft-made claim that power relations are central to school bullying, the dissertation focuses specifically on the interconnectedness of school bullying and power relations within the specific context of Vietnamese lower secondary schooling. The dissertation is based on extended ethnographic fieldwork in two lower secondary schools in the north-eastern Vietnamese port city of Haiphong. READ MORE

Searchphrases right now

• PERFORMANCE MANAGEMENT DISSERTATIONS
• nanokompositer
• gröna material
• funktionella hybrider
• nanofibrillering
• online behaviour
• extinction events
• Dielectric constant
• congestion management
• cost effective analysis

Popular searches

• gel-electrophoresis
• CD4 T cells
• heavy quarks
• syllabification
• integrated product development
• health habits
• stroke quality
• multiple items
• beta2-microglobulin
• kinetiska parametrar

Popular dissertations yesterday (2024-04-05)

• Eating disorders, eating pathology and ESSENCE
• Genetic and environmental influences on antisocial behavior from childhood to emerging adulthood
• Prehistoric stonework in the Peruvian Andes : a case study at Ollantaytambo
• Corporate Disclosures Regulations : Social Solution or a Problem?
• Hydronephrosis in childhood : An experimental and clinical study
• Methods for Synchrophasor-Based Power SystemInstability Detection and HVDC Control
• Capillary electroseparations in pharmaceutical analysis of basic drugs and related substances
• Gas discrimination for mobile robots
• Workplace health promotion and employee health in municipal social care organizations
• Diffusive Combustion of Ethanol in a Dual-Fuel Direct Injection Compression Ignition Engine
• Popular complementary terms: essays, phd thesis, master thesis, papers, importance, trend, impact, advantages, disadvantages, role of, example, case study.

See yesterday's most popular searches here . Dissertations.se is the english language version of Avhandlingar.se .

• Share full article

Advertisement

Are Smartphones Just a Scapegoat for Our Unhappy Children?

Why ditching phones won’t save the kids..

This transcript was created using speech recognition software. While it has been reviewed by human transcribers, it may contain errors. Please review the episode audio before quoting from this transcript and email [email protected] with any questions.

I feel like all the trains in Italy. Cancellato!

Cancellato! I once got stuck in Pisa when they canceled the trains.

Yeah. It was a great opportunity for me to tell my kids about the failures of European social welfare capitalism.

Oh, good. Good.

The kids love that. [MUSIC PLAYING]

From New York Times Opinion, I’m Ross Douthat.

I’m Michelle Cottle.

I’m Carlos Lozada.

And I’m Lydia Polgreen.

And this is “Matter of Opinion.”

We’re — [LAUGHTER] no, we’re reunited. We’re all recording —

And it feels so good.

(SINGING) Reunited —

— in the same room together. I could almost touch all of my co-hosts.

Please don’t.

And then Carlos would call H.R.

But I will not because we’re talking about disconnection, virtual alienation. We’re going to talk about kids and smartphones.

Dun, dun, dun.

So there is a lot of evidence that kids — American kids, maybe kids around the developed world — are not doing so well over the last 10 years. Not just in a sort of kids being kids way, but there is a real shift in rates of depression, anxiety, mental illness diagnoses, suicide and suicidality. All of these things are up for young people, and so are hours spent on smartphones.

And there’s a widely circulated theory, seemingly plausible, but also hotly contested, that screens and social media are responsible for making teenagers, especially, unusually unhappy. So this is a big problem since screens and smartphones are sort of the defining technologies of our age. And I’m hoping we can resolve this problem here today in a podcast. [LAUGHTER]

Maybe not. But maybe we can debate some solutions, responses, and talk about what might be going too far in our desire to protect kids. So let’s get started with a personal question. For those of you, us, who have kids or teenagers, in the house or out of the house, what are the rules for smartphones in your home?

So I’ve got the oldest, I think. Mine are 20 and 18. So right now there are no rules. It’s obviously a free for all. But when they were —

It’s a vicious landscape.

It’s “Lord of the Flies” at Michelle’s house.

The only contact I get is when somebody wants to text me for money. But —

That was me, so I’m sorry about that, but —

Dang, Ross! So going back, though, I think we hit the smartphone button when they were in seventh grade because that’s when they went to middle school, and that’s kind of just — that was the standard around here. And then we tried to set limits on screen times and things like that. And I have to say the pandemic made that infinitely more complicated.

So first rule of parenting is you don’t talk about parenting. [LAUGHTER]

No, the first rule of parenting is that each kid is different, right? So I have three kids. One kind of mid-teens, one early teens, and one is finishing up elementary school. My oldest, who is 16, has a smartphone. He only got it last year. And he uses it mainly to be in touch with us, with his editor at the student paper, with his friends.

My daughter who’s 13 has one of those little mini old-fashioned iPods which she uses to communicate with text and email with friends, with her dance group or her orchestra friends, and to listen to books. And my youngest, who’s 10, wants an Apple Watch, but isn’t getting it. [MICHELLE LAUGHS]

They don’t use any kind of social media. We don’t ban it, but we discourage it. And part of the trick is that they really don’t have a lot of free time between theater, or dance, or baseball, or student journalism. They don’t have a lot of time to go on social media. We’re keeping our fingers crossed that it stays that way, at least until they reach the age of reason, the age of reasonableness. [LAUGHS]

We’re still waiting on that at my house.

But that is —

Good luck with that.

— the way it works so far in our home.

Huh, that’s interesting. I mean, I don’t have kids, as you all know. But I’ve tried to imagine what rules and limits would I want to set. And I think in some ways, Carlos, what you’re describing, it sounds like both an ideal but also very tough. Because in order to make sure that your kids have really, really full lives, it probably requires a lot of engagement from you and your wife. And living in the modern world —

Little sleep, yes. [LAUGHTER]

— we’re all very, very busy. And —

And think about the way that I grew up — and we’re all Gen X — and I had perhaps an extreme version of the free range childhood. Even though my mother was technically a stay-at-home mom, she did not want to see us home all day. And we sort of ran wild. It’s hard for me to imagine wanting anything different for my own children. But I realize that’s not the world that we live in.

But Ross, you have the youngest kids of all of us. So you’re just staring this down, and you have a bunch of them. So —

We — well, yeah, and the oldest is 13, and she still does not have a phone of any kind. And my assumption is that we will crack and get her some kind of what my kids call a dumb phone next year for eighth grade. She is trying to negotiate with me to get a smarter phone, insisting that she would never use social media. She will probably invoke the idea that she’s so busy, the excuse —

The lie my feeds are feeding me?

The lie your kids are feeding you. But it is very unlikely that we would crack on that. But we really haven’t entered fully into this world. But I want to pick up on Lydia’s comment about the free range childhood, because one of the reasons we’re talking about this this week is that this debate has been running for a while, but it’s resurfaced because of a new book by Jonathan Haidt called “The Anxious Generation,” that’s basically Haidt making the case not just that there’s something specific about, let’s say, the social life of teenage girls on Instagram or TikTok or the social life of teenage boys playing video games, that’s a problem for mental health, but also that this is a substitute for exactly the kind of childhood you’re describing.

So it’s not just the screens themselves are the devil. It’s also that the screens themselves have reshaped social life and eliminated certain features of childhood that taught people how to be adults, taught people how to navigate interpersonal dynamics in person, how to communicate with the opposite sex, how to settle fights on the playground with their friends, this kind of thing.

Haidt has a number of critics who basically say he’s making a correlation/causation mistake. That, yes, it happens to be that mental health has gotten worse over the smartphone era, but that does not prove that the phones are the problem. Do you guys buy the argument?

I mean, I’ve read the competing correlation/causation arguments, and, of course, have looked in detail at every single study and weighed them —

I have been personally running regression analyses in my spare time.

I was going to say, I have so many histograms, you would not believe it. [LAUGHTER]

You would not believe the number of histograms. But to me, the bigger question is one of emphasis. Should we be more concerned by the vacuum that was created by putting children into a much more protective bubble? Is the problem that we need to solve the transformation of childhood into what many kids experience as much more tightly controlled and scheduled and mediated through parents as opposed to mediated through your friend groups and learning how to build your own boundaries and relationships and things like that, or do we tackle the problem at the level of smartphones?

Look, I personally believe that I have a dysfunctional relationship with smartphones. And so it’s very easy for me to look at kids and be like, oh, yeah, of course they must also have a very dysfunctional relationship. But honestly, I don’t know.

I think it’s always a problem to put too much emphasis on any one particular culprit, and it is generally our impulse to blame technology. I mean, TV — did TV ruin kids? Probably. But that is —

I mean, look at us.

— one of the panics that we had. And then for years everyone told us that violent video games absolutely positively were turning our children into sociopaths. This, on one level, is what we do. We decide it’s something that we can tackle simply or blame simply. But then there’s 30 questions I have as to what we’re really worried about here.

I mean, are we upset about kids sitting around on their phones rather than playing outside, worried about them doing less in-person socializing, worried about them becoming addicted to external affirmation from their online groups, upset about them having access to scary news and inappropriate information, upset that they’re not as independent, worried about bullying? I mean, there’s so many things that fall into this category that we’ve just decided are all about smartphones.

So I think the virtue of the Haidt argument, it’s a technology is doing something bad argument that has a pretty narrow and focused zone of concern. And that zone of concern is the fact that young people report being unhappier as young people than was the case generally in our cohort and preceding generations. And this pretty clearly tracks to a kind of point of divergence.

I think 2012 to 2014 is sort of a break point in the data. If you just look at the charts that Haidt puts together, you say, well, yeah, something clearly happened in this window that is not just teenagers or teenagers. You need some explanation. And that’s why his critics have tended to also put forward contingent time bound speculations. Like it’s the aftermath of the financial crisis, it’s the rise of school shootings and school shooting drills. There is, I think, a quest for a particular kind of explanation because you have this divergence in the data.

Now, there is also the response or argument that what we’re seeing here is just better diagnosis. That kids have had these mental health problems all the time, and, for better or worse — many people would say for better, some people would say for worse — we’re talking more about mental health. Maybe that’s the whole divergence. We’ve become more open to these discussions or more likely to offer these diagnoses, and that alone is enough to —

We’re a therapeutic society.

Right. We’re a therapeutic society and it’s finally achieved takeoff, and that’s where we are now. I try to be skeptical of the Haidt thesis because it confirms my priors. Like Lydia, I have a toxic relationship to my smartphone. I don’t use that much social media. But the social media I use I’m addicted to and make the excuse that it’s part of my job. So I have a natural inclination to buy into the argument. So I try and be more skeptical of it. But I think that right now it’s a pretty parsimonious explanation for at least some of this divergence.

You’re saying parsimonious in a positive sense?

Right. In a positive — in a positive sense, yeah.

Because the data are quite dramatic. I mean, I was looking for other sources of information about this because Haidt, in his book, talks about, actually, this data is global. These are things that we’re seeing in other countries. So I was looking at other alternative sources of data on this.

And there was a UNICEF report that was published in 2020. And it’s really interesting actually how much of an outlier the U.S is. And this is a place where I actually have a significant amount of skepticism about the Haidt book. It counted 38 of the wealthiest countries in the world, and the United States was 32nd in terms of mental well-being on this list. And the top five were not what you would expect. They were the Netherlands, Cyprus, Spain, Romania and Denmark. So this is just —

I mean, I would have predicted Romania.

Yeah, absolutely.

But maybe not the rest.

Absolutely. The reports in this study on the effect of technology use was one quarter the size of the effect from bullying, for example. So I came to this information saying, like, oh, yeah, this all sounds plausible. But the more I dug into other sources and other cuts at looking at this question of child happiness, the more skepticism that I had that this one explanation was enough. I think you need to take the changes of childhood and technology together.

Haidt does push back against the critics who say it is a monocausal explanation by saying that, look, I’m talking about the changes to the independent childhood that we had in the ‘70s or the ‘80s versus today. And I accept that defense of his. But in some ways, if you look at just his body of work, even just his “Atlantic” articles over the years, he does feel like he’s beating the same drum over and over again with slightly different speeds.

I read each piece individually and I feel persuaded. I read them together and I feel suspicious, right? I don’t mean suspicious in an ill intent on the part of the writer kind of way. But I think of a worldview that maybe explains too much.

And I also wonder if different kids are different. So when I was a kid, my mother was obsessed — obsessed with us not watching too much television because she thought it was going to rot our brains. She would come home and she would put her hand on the top of the TV set. And if it was warm, she’d know — [LAUGHTER]

— that we’d broken the rules. And my mother did not mess around. She’d unplugged the TV. She’d get out a pair of scissors and she’d snip off the plug.

As a punishment, so that we would not watch it again.

Totally, totally badass.

That’s real parenting.

But I want to tell you — I want to tell you, it’s even better parenting. You know what my brothers and I did? We would go to RadioShack and we would buy a plug, and then we taught ourselves how to reattach a plug and then not make it look like —

Yeah, but this is exactly —

You have skills.

This is the bypass of childhood.

Kids are going to bypass any form of control over —

But Haidt would say that is the kind of childhood creativity that is being lost, the ability to do end-arounds when your parents —

To McGuyver your TV set!

Ross you mentioned school shootings. I mean, this month, believe it or not, will mark 25 years since Columbine. And the kids that Haidt is talking about are kids that have grown up entirely in a world formed by that experience. I don’t just mean Columbine, but I mean the experience of lockdown drills in schools, knowing that every day they’re going to a place where they’re meant to be taught and educated and protected, but that they feel at risk.

The reason my son has a smartphone is because there were bomb threats at his school, which he covered as a student journalist. But that’s why he has a smartphone to begin with.

I find that argument totally unpersuasive to explain the divergence that you see —

Oh, no, no, I meant —

— starting in the early 2010s.

No, I’m not saying — I’m not saying —

It doesn’t track, particularly, with the rise of school shootings. It doesn’t track at all with general violence in schools, which was much higher in the 1980s and early 1990s than today. And it does, allowing Lydia’s point that the data is complex, it does show up — the teenage mental health issue — in lots of other countries that don’t have active shooter drills and so on.

What’s odd in this debate is that Haidt is making an argument that in a way tracks pretty well with a lot of traditional left wing preoccupations. He’s saying a bunch of big rapacious capitalist entities, in order to make a profit, are exploiting your children and destroying their mental health.

And a lot of people on the left are like, no, that’s not satisfying enough. It has to be something that Republicans did, right? Because Silicon Valley isn’t coded as Republican. It has to be climate change because we can blame Republicans for that. It has to be school shootings because we can blame Michelle’s Southern relatives and their guns for that.

That feels very sensitive.

I don’t know. It’s like you’re just looking for — I mean, there are many reasons why children can be anxious all at once. I worry a little bit about Haidt pointing to smartphones as the overwhelming reason. There are multiple reasons why any one kid can be having trouble.

And another — and this is where I was headed. I wasn’t saying that therefore the explanation is school shootings. In the panoply of possible reasons for kids to be struggling, another is — Lydia and Ross have mentioned that you have your own toxic addictive relationships with your phones. I mean, these are also kids who have grown up with parents —

With parents, yes.

— who are entirely tethered to their devices and who basically — a few years ago, I read this book by Sherry Turkle called “Reclaiming Conversation,” and she had a line that has stuck with me since then where she says that all our relationships now come with the assumption of divided attention. And that is all the more so with children seeing the divided attention that their parents, already distracted and busy and tired parents, give to them.

All right, let’s take a break. And when we come back, we’ll talk about whether we should be even looking for solutions here. And if so, what they might be.

[MUSIC PLAYING]

One of the things that I’m interested in is when you start talking about what to do about it, then it gets really sticky, though. And I think one of the things that does bother me is when the states start looking at, well, how are we going to save our children?

They start talking about putting limitations on what kids can do on their phones. And you quickly get into questions of First Amendment rights and things like this. None of which is going to matter if you’ve got kids who are watching their parents sit on their phones all day long 24/7. That’s like lecturing kids not to do drugs while you’re sitting there dropping acid.

So there is a question about how we’re going to tackle this. And this just seems to be one of those areas that we rush to because it seems very easy to tackle. We’ve had several states try and limit what kids can do and what their social media account age is. But it’s a lot of constitutional questions, and a lot of time and energy going into something that doesn’t strike me is going to be all that useful.

I mean, just on the personal side, Michelle’s first, right, since you’re the senior parent in this conversation, meaning the one with the most experience.

Yeah, call me old.

The one with the most experience.

Walk that one back, Ross.

The wisest.

Your kids are basically through high school into college, right?

Mhm. And if you look back over the last 10 years, setting aside the state, setting aside government, are there things that either you as a parent or you as a consumer of school-based services — are there things that you wish you had done differently or things that you wish your kids’ schools had done differently?

So, now, one problem that I do think parents have is once you hit a certain age with kids, you can’t limit their screen time because they’re doing homework online. So I would try to keep limits on my kids’ screen time, and they would just be like, well, we’re just doing math homework on our computer.

And unless you are going to stand over that child every minute — and let’s be clear, it wasn’t a question of I didn’t want to put in the time or effort to stand over my child. It’s also, you can’t police your children like that. I mean, you have to give your children a little bit of freedom to screw up or whatever. So it was absolutely impossible on some level.

It got even worse during Covid.

Yeah. And COVID —

It was impossible, where it all got conflated.

— completely — my kids’ friends and my kids themselves had real Covid isolation issues. And it became really dark at certain times. And it was really hard to tell whether being able to connect with their friends on their smartphones was helping or hurting or whatever because technology has taken over our lives. I tend to think that as a society when we’ve given up on being reasonable about something, we then try to put limits just on the kids.

I asked my daughter, who’s 13 — I told her that we were going to have this conversation, and I asked her what she thought about rules and limits and bans. And she said she didn’t have a problem with there being rules and limiting access to certain things. She’s like, we do that for lots of other stuff that seems OK. But maybe you all should have some limits, too. She felt that —

Her reaction was that it shouldn’t just be for children. That a lot of bad things happen on social media when adults use social media.

Yeah. I don’t how we think we can save our children if that’s the approach that we’re going to take.

Well, I guess I’ll speak up for the kids first approach then. I completely agree that obviously the example that you set for your kids makes a huge difference. And I obviously think social media and smartphones have a deranging effect on adults too. But childhood is both a era of greater personal social emotional vulnerability than adulthood and also a period in which we take for granted that it is possible to impose substantial regulations that in a free society we can’t impose on adults. And we do this with lots of things. We do this with driving. There’s lots of terrible drivers on the road, but we don’t say, oh, we can’t let adults drive because we’re showing kids that they’ll be bad drivers when they grow up. Same with alcohol, tobacco products, all of these things.

And we can argue back and forth about where the exact line should be. But I do think that social media age requirements, things like banning smartphones from schools and so on, are just obvious first steps, that don’t get you close to fixing all of the problems, but are things that you should just do and see what happens.

As you were talking, I was thinking about some of the cultural differences about this. I don’t think there’s any society that’s like, OK, we want to teach our children to have a healthy relationship with tobacco. But when it comes to alcohol, there is a different attitude. Alcohol is seen as an important source of conviviality, of pleasure, of enjoyment, and cultivating one’s temperate enjoyment of it is something that starts relatively early in life.

And let’s set social media aside for just one second and just talk about technology and screens in general. We are all going to live in a world where screens are going to be a part of it. And I’m not going to give my baby a bottle filled with watered-down wine, right? But I might give my 13-year-old, a very, very small glass of wine watered down with seltzer at Thanksgiving or whatever. That to me feels more of an approach that I could get behind rather than just ban it. And I think about my own consumption of television. I mean, I told that very funny story about my mom and cutting the cord. The reality is that if there is a television on in a room, I cannot pay attention to anything else. I mean, if there was a television over the other side of your shoulder, Ross, I would be so distracted.

Fascinating.

Whereas, my wife, who grew up in a household where the TV was on all the time, can just tune it out. It’s just white noise to her. So I guess if we’re going to live in a world with these technologies, how do we prepare kids to have healthy relationships to them, to turn them into tools that can serve them? The problem is if it just takes over your entire life. [LAUGHS]

To be the optimist — the cockeyed optimist here, right? Lydia brought up tobacco. The United States had a massive public health campaign against tobacco that, in fact, did lead to dramatic changes in smoking’s social acceptability and all of these things.

And there is this range of proposals in Congress. There’s the Kids Online Safety Act, which would require tech platforms to make various design changes. Protect Kids on Social Media Act, which would establish an age minimum and parental consent. And then there’s this general — there’s a lot of grandstanding in Congress about what Meta has done wrong and the different ways these platforms have exploited kids.

And to the extent that you find the public psychological health arguments around tech and social media persuasive, is there any law or public health measure that you would like to see pass or imagine would be helpful? Or does it just not seem like a political problem?

I’m not convinced it’s a political problem. And I also think a lot about the ways in which such laws could be used. As a queer person, I think about kids who are trying to figure out who they are and what are the places that they might connect with other people like them.

Obviously, I grew up in a connection desert growing up in East and West Africa. We didn’t even have a home phone for a while. So I don’t romanticize the disconnected life at all. I think loneliness has lots of different facets to it. And I think that IRL friendships are great. But friendships over distance I think can be very, very meaningful. We have a whole literature of epistolary friendships —

Letter writing is another lost art —

Another lost art. I mean —

— that the smartphone has killed.

Yeah. Voice memos on the other hand — [LAUGHTER] so, yeah, I’m skeptical about the role of legislation in this area. I mean, I think, actually, profound social changes are needed. I think that we need to rethink the way that we treat children in society, the amount of freedom, the amount of autonomy that we give them. Obviously I believe that they need to be protected from dangerous things. But — and this is just my bias from my own experience, having been a very, very independent kid — I’m a strong believer in child independence.

I think laws sometimes reflect social changes and sometimes anticipate them. And I would be open to a lot of the kind of reforms that Jonathan Haidt suggests, to some degree, of limiting access to social media. I’m persuaded by the potential educational impact of smartphone bans or at least severe reductions in smartphone use in schools.

At the same time, I still believe that there is a multiplicity of factors behind the mental health and well-being crisis that we’re seeing with kids in the United States. So I’m both open to them, but skeptical that they would solve the underlying issue that we’re facing.

All right, well let’s close out by just looking forward a little bit, because I’m curious where you guys think this debate will be in 10 or 20 years, maybe at the point where some of our children are parenting themselves.

Oh, I can’t wait for that.

Can’t wait for that. And grandchildren reversing the birth dearth. [LAUGHTER] Anyway —

Different podcast, Ross. Different podcast.

Different episodes.

But isn’t it all the same episode, Lydia? I’m curious, generally, because there’s also a way in which when technological change happens, sometimes by the time you figure out what’s going wrong in one particular dispensation, we’re headed into a new dispensation, right?

So just hearing the way that schools rely on the internet and tech for assignments and so on, does that survive the age of ChatGPT and AI assistants? Is it possible that we’re going to head into a landscape where all of education is going to have to recalibrate itself?

They’re never going analog again, Ross.

Well, that’s —

They’re not going back to analog. It’s too — it’s not going to happen.

OK, but so then what is the world on the other side of AI or on the other side of any other looming technological change, on the other side of virtual reality?

We don’t know. That’s what’s so great about it. Could you have predicted where we are now 20 years ago? I don’t think you could have. Come on.

I mean once that’s true once Elon Musk has put chips in all of our brains, then we’ll experience the singularity and we’ll know what’s happening.

All right, let me —

No, no, I have a real answer here.

Let me — all right, Carlos — but no, let me first say, I am detecting just an incredible level of fatalism from all three of you about technological change.

And I agree with all of you that, yes, of course, we are not undoing the internet revelation — excuse me —

See, Freudian — paging Dr. Freud.

We know what you want, Ross.

We know what I want. I want the singularity, too. But it seems to me that there’s a huge question here, which is, are we going to master these kind of technologies or be mastered by them? And I feel like, are all of you just content to drift into the Neuralink future? Carlos, the humanist, I appeal to you to close us out with resistance. Come now —

Hashtag resistance.

— speak for paper, speak for print, speak for analog.

I only read on paper. Here I am saying that on a podcast. Who’s read “Canticle for Leibowitz“?

Well, you know I have. That’s a —

It’s a book that I highly recommend. It’s a book in which the existential perils of technology are taken so seriously that we attempt to fully simplify our lives to purge ourselves of these technologies. Yet, inevitably we recreate them with the same destructive results. And just because it fails, it doesn’t mean that we shouldn’t make the attempt.

So I think it’s foolish to be optimistic in this world, but it is not foolish to be hopeful. But even as we make those attempts, I’m skeptical of a silver bullet answer to the problem that we’ve discussed today. We will simply move on to a new version of it, which then we will look back with longing on this simpler time. The way that Lydia talked about the television story, we’re going to talk about trying to — you remember back in the 2000s when we tried to regulate smartphones? And we didn’t know that the fill in the blank was coming next and that was going to be even more insidious and destructive.

Brain chip. Lydia is right. Brain chip.

No, but I think that’s — I think that’s a really good way of putting it, Carlos. And I think that the reality is that things stop being cool. Facebook has been abandoned to the boomers and —

Oh, you cannot pay kids to be on Facebook.

— other social media. And I think it’s one of those things that’s seen as a punch line. But kids reject the things that their parents are into, and are addicted to, and want to talk about, and want to focus on. And I think that things become not cool. And that’s definitely a thing that I’m seeing among young people that I know, that they’re like, you know what’s not cool is spending all your time on social media.

And on that note, I’m going to return home and explain to my 13-year-old daughter that it is her duty to make the smartphone uncool in her middle school and high school. And we’ll leave it there. And when we come back, we’ll get hot and cold.

Just tell her how cool you think it is and that’s going to do it.

All right, guys, it’s time to get hot cold. Who’s got one this week?

I’m hot cold this week.

So I just returned from “Matter of Opinion”‘s official vacation destination, which is Italy.

And I happened to be there during Holy Week. And so we did Palm Sunday mass and Easter Sunday mass in Venice. The Palm Sunday mass, it was, first of all, very few people. And we thought like, how on Earth, in Venice, on Palm Sunday, there are only 50 people in this church? Because we were at the Latin and Gregorian mass service. And we experienced —

Carlos, be still my heart.

My children experienced the Latin mass, which they had not done up to this point in their lives. And it was wonderful. We had an absolutely — see, I was afraid that this —

Ross is going to weep.

I was afraid that this would trigger an outpouring of Rossness. But it was so beautiful.

In a good way!

Just to stipulate for listeners, who may have some stereotypical view of me, I do not attend the traditional Latin mass.

Neither do I. And I went to Catholic —

I went to Catholic grade school, high school, and college. So I’ve been to many variations of our liturgy. And my wife and I were trying to explain to the kids, even whispering during the service, that they had entered a sort of time warp where they got to experience something that is a lot less common these days.

And I think of myself as very much a Vatican II Catholic. I’m all in favor of the opening up of the liturgical experience, of the role of laypeople in the church. But it took a long time. Palm Sunday mass is generally long. And the Latin mass version is, I think, a good bit longer than normal.

But even so, it was both a wonderful experience for me to think about a church before the church that I have known, and also for my children to have a sense of this experience and to have them feel — I hope some small part of them felt part of a much longer history and tradition.

That’s so beautiful.

You heard it here. I am hot on the Latin mass.

Ross is speechless.

I don’t have anything. I can’t add anything.

I’m hot on the Latin mass.

That sounds like a really, really amazing experience. I’m glad for you and your family.

That is downright beautiful.

Amazing. OK, we got to stop there before anything happens to spoil the Catholic mood.

Don’t say a word.

He says to the protestant!

He says to Michelle.

To the Southern Protestant.

I have not brought the Southern Baptist into this discussion!

OK, good. Guys, it’s been a pleasure. We’ll be back next week.

See you next week.

Good to be back.

Bye, guys. [MUSIC PLAYING]

Thanks so much for joining us. Give us a follow on your favorite podcast app and leave us a nice review for “Matter of Opinion” while you’re there, so other people can know why they should tune in, too, mostly for the Latin mass recommendations. If you have a question you think we should think about next, like why the Latin mass is awesome, share it with us in a voice — [LAUGHING]

— OK. Sorry. [LAUGHTER]

Carlos, this only happens once. I have to milk it. If you have a question you think we should think about next, share it with us in a voicemail by calling 212-556-7440 or send us an email by writing to [email protected].

“Matter of Opinion” is produced by Phoebe Lett, Sophia Alvarez Boyd, and Derek Arthur. It’s edited by Jordana Hochman. Our fact-check team is Kate Sinclair, Mary Marge Locker, and Michelle Harris. Original music by Isaac Jones, Carole Sabouraud, and Pat McCusker. Mixing by Pat McCusker. Audience strategy by Shannon Busta and Kristina Samulewski. And our executive producer, as always, is Annie-Rose Strasser.

[SINGING IN LATIN]

• April 5, 2024   •   38:40 Are Smartphones Just a Scapegoat for Our Unhappy Children?
• March 29, 2024   •   36:17 Finding the Line Between Celebrity and Politician With Tressie McMillan Cottom
• March 22, 2024   •   38:05 Obama, Trump, Pence: Revelations From Reading the Swamp
• March 15, 2024   •   36:00 What Do You Do if You Hate Both Biden and Trump?
• March 8, 2024   •   41:36 Trump 2.0: ‘A Blueprint for Retribution’
• March 1, 2024   •   37:16 The Pro-Life Movement Had a Plan Post-Roe. The G.O.P. Didn’t.
• February 23, 2024   •   38:30 Will the Economy Favor Biden or Trump? Paul Krugman Weighs In.
• February 16, 2024   •   34:40 The Presidential Fitness Test
• February 9, 2024   •   35:37 Our Super Bowls, Ourselves
• February 2, 2024   •   42:02 The Gender Split and the ‘Looming Apocalypse of the Developed World’
• January 26, 2024   •   36:53 Could Israel Cost Biden the Election?
• January 19, 2024   •   35:20 Why Is There No Effective Anti-Trump Constituency?

Hosted by Michelle Cottle ,  Ross Douthat ,  Carlos Lozada and Lydia Polgreen

Listen to and follow ‘Matter of Opinion’ Apple Podcasts | Spotify | Amazon Music

It’s not just bad vibes — America’s kids are not OK. As study after study shows worsening youth mental health, a popular theory has emerged: The rise of smartphones and the addictive nature of social media is making young people miserable. But can it really be that simple?

This week on “Matter of Opinion,” the hosts debate the myriad possible factors contributing to teenagers’ unhappiness, and discuss how parents, schools and the government can protect kids without doing further harm. Plus, a sui generis Lozada family vacation.

(A full transcript of this audio essay will be available within 24 hours of publication in the audio player above.)

Recommended in this episode:

“ The Anxious Generation ,” by Jonathan Haidt

“ Reclaiming Conversation ,” by Sherry Turkle

“ A Canticle for Leibowitz ,” by Walter M. Miller Jr.

Thoughts? Email us at [email protected] .

Follow our hosts on X: Michelle Cottle ( @mcottle ), Ross Douthat ( @DouthatNYT ) and Carlos Lozada ( @CarlosNYT ).

“Matter of Opinion” is produced by Phoebe Lett, Sophia Alvarez Boyd and Derek Arthur. It is edited by Jordana Hochman. Mixing by Pat McCusker. Original music by Isaac Jones, Efim Shapiro, Carole Sabouraud, and Pat McCusker. Our fact-checking team is Kate Sinclair, Mary Marge Locker and Michelle Harris. Audience strategy by Shannon Busta and Kristina Samulewski. Our executive producer is Annie-Rose Strasser.

Follow the New York Times Opinion section on Facebook , Instagram , TikTok , WhatsApp , X and Threads .

Michelle Cottle writes about national politics for Opinion and is a host of the podcast “Matter of Opinion.” She has covered Washington and politics since the Clinton administration.  @ mcottle

Ross Douthat has been an Opinion columnist for The Times since 2009. He is the author, most recently, of “The Deep Places: A Memoir of Illness and Discovery.” @ DouthatNYT • Facebook

Carlos Lozada is an Opinion columnist and a co-host of the weekly “Matter of Opinion” podcast for The Times, based in Washington, D.C. He is the author, most recently, of “ The Washington Book : How to Read Politics and Politicians.”  @ CarlosNYT

Lydia Polgreen is an Opinion columnist and a co-host of the “ Matter of Opinion ” podcast for The Times.

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• Campbell Syst Rev
• v.17(2); 2021 Jun

Effectiveness of school‐based programs to reduce bullying perpetration and victimization: An updated systematic review and meta‐analysis

Hannah gaffney.

1 Institute of Criminology, University of Cambridge, Cambridge UK

Maria M. Ttofi

David p. farrington, executive summary/abstract.

Bullying first emerged as an important topic of research in the 1980s in Norway (Olweus), and a recent meta‐analysis shows that these forms of aggression remain prevalent among young people globally (Modecki et al.). Prominent researchers in the field have defined bullying as any aggressive behavior that incorporates three key elements, namely: (1) an intention to harm, (2) repetitive in nature, and (3) a clear power imbalance between perpetrator and victim (Centers for Disease Control and Prevention; Farrington). There are many negative outcomes associated with bullying perpetration, such as: suicidal ideation (Holt et al.), weapon carrying (Valdebenito et al.), drug use (Ttofi et al.), and violence and offending in later life (Ttofi et al.). Bullying victimization too is associated with negative outcomes such as: suicidal ideation (Holt et al.), anxiety, low self‐esteem and loneliness (Hawker& Boulton). Therefore, school bullying is an important target for effective intervention, and should be considered a matter of public health concern.

The objective of this review is to establish whether or not existing school‐based antibullying programs are effective in reducing school‐bullyng behaviors. This report also updates a previous meta‐analysis conducted by Farrington and Ttofi. This earlier review found that antibullying programs are effective in reducing bullying perpetration and victimization and a primary objective of the current report is to update the earlier analysis of 53 evaluations by conducting new searches for evaluations conducted and published since 2009.

Search Methods

Systematic searches were conducted using Boolean combinations of the following keywords: bully*; victim*; bully‐victim; school; intervention; prevention; program*; evaluation; effect*; and anti‐bullying . Searches were conducted on several online databases including, Web of Science, PscyhINFO, EMBASE, EMBASE, DARE, ERIC, Google Scholar, and Scopus. Databases of unpublished reports, such as masters' and doctoral theses (e.g., Proquest) were also searched.

Selection Criteria

Results from systematic searches were screened thoroughly against the following inclusion criteria. To be included in this review, a study must have: (1) described an evaluation of a school‐based antibullying program implemented with school‐age participants; (2) utilized an operational definition of school‐bullying that coincides with existing definitions; (3) measured school‐bullying perpetration and/or victimization using quantitative measures, such as, self‐, peer‐, or teacher‐report questionnaires; and (4) used an experimental or quasi‐experimental design, with one group receiving the intervention and another not receiving the intervention.

Data Collection and Analysis

Of the 19,877 search results, 474 were retained for further screening. The majority of these were excluded, and after multiple waves of screening, 100 evaluations were included in our meta‐analysis. A total of 103 independent effect sizes were estimated and each effect size was corrected for the impact of including clusters in evaluation designs. Included evaluations were conducted using both randomized ( n  = 45; i.e., randomized controlled trials/RCTs) and nonrandomized ( n  = 44; i.e., quasi‐experimental designs with before/after measures; BA/EC) methodologies. All of these studies included measures of bullying outcomes before and after implementation of an intervention. The remaining 14 effect sizes were estimated from evaluations that used age cohort designs. Two models of meta‐analysis are used to report results in our report. All mean effects computed are presented using both the multivariance adjustment model (MVA) and random effects model (RE). The MVA model assigns weights to primary studies in direct proportion to study level sampling error as with the fixed effects model but adjusts the meta‐analytic standard error and confidence intervals for study heterogeneity. The RE model incorporates between‐study heterogeneity into the formula for assigning weights to primary studies. The differences and strengths/limitations of both approaches are discussed in the context of the present data.

Our meta‐analysis identified that bullying programs significantly reduce bullying perpetration (RE: odds ratio [OR] = 1.309; 95% confidence interval [CI]: 1.24–1.38; z  = 9.88; p  < .001) and bullying victimization (RE: OR = 1.244; 95% CI: 1.19–1.31; z  = 8.92; p  < .001), under a random effects model of meta‐analysis. Mean effects were similar across both models of meta‐analysis for bullying perpetration (i.e., MVA: OR = 1,324; 95% CI: 1.27–1.38; z  = 13.4; p  < .001) and bullying victimization (i.e., MVA: OR = 1.248; 95% CI: 1.21–1.29; z  = 12.06; p  < .001). Under both computational models, primary studies were more effective in reducing bullying perpetration than victimization overall. Effect sizes varied across studies, with significant heterogeneity between studies for both bullying perpetration ( Q  = 323.392; df  = 85; p  < .001; I 2  = 73.716) and bullying victimization ( Q  = 387.255; df  = 87; p  < .001; I 2  = 77.534) outcomes. Analyses suggest that publication bias is unlikely. Between‐study heterogeneity was expected, given the large number of studies included, and thus, the number of different programs, methods, measures and samples used.

Authors' Conclusions

We conclude that overall, school‐based antibullying programs are effective in reducing bullying perpetration and bullying victimization, although effect sizes are modest. The impact of evaluation methodology on effect size appears to be weak and does not adequately explain the significant heterogeneity between primary studies. Moreover, the issue of the under‐/over‐estimation of the true treatment effect by different experimental designs and use of self‐reported measures is reviewed. The potential explanations for this are discussed, along with recommendations for future primary evaluations. Avenues for future research are discussed, including the need further explain differences across programs by correlating individual effect sizes with varying program components and varying methodological elements available across these 100 evaluations. Initial findings in the variability of effect sizes across different methodological moderators provide some understanding on the issue of heterogeneity, but future analyses based on further moderator variables are needed.

1. PLAIN LANGUAGE SUMMARY

1.1. interventions to reduce school bullying perpetration and victimization are effective.

Bullying is a ubiquitous form of aggression in schools worldwide. Intervention and prevention programs targeting school bullying perpetration and victimization are effective, yet more research is needed to understand variability in effectiveness.

The main findings of our review are that bullying programs were effective in reducing bullying perpetration outcomes by roughly 18–19% and bullying victimization by roughly 15–16%. There are substantial variations in effects, and the reasons for these variations require further research.

1.2. What is this review about?

Bullying is defined as aggressive behaviors that occur repeatedly over time between two or more individuals. Typically, there is a clear power imbalance between victims and bullies, either socially or physically. Furthermore, bullying behaviors are those that are committed intentionally to harm the victim.

What is the aim of this review?

The aim of this review is to summarise findings from studies of the effectiveness of school‐based antibullying programs in reducing both bullying perpetration and victimization will be reported. The review summarizes 100 studies, with the largest number being from the United States.

1.3. What studies are included?

To be included in this review, primary studies must have evaluated a specific intervention program that targeted bullying perpetration and/or victimization outcomes in school‐aged children, that is, typically between four and 18 years old. Studies must have used two experimental groups of children, one that received the intervention, and one that did not, and applied quantitative measures of bullying behavior (perpetration and/or victimization) that coincided with our operational definition of bullying.

Our final meta‐analytic review includes 100 studies of the effectiveness of antibullying programs. The largest number of studies came from the United States, with most other studies from Canada and Europe.

1.4. What are the findings of this review?

Antibullying programs are effective in reducing bullying perpetration outcomes by roughly 18–19% and bullying victimization by roughly 15–16%.

Variability in the effectiveness of antibullying programs was associated with differences in methodological designs, types of programs and geographical regions. Interventions evaluated using age cohort designs collectively gave the largest overall effect for both bullying perpetration and bullying victimization.

Limitations of the results are similar to those of previous reviews; for example, the reliance of self‐reported measurements of bullying may suggest the change is in reports of bullying perpetration/victimization and not behavioral change.

1.5. What do the findings of this review mean?

The findings indicate that school‐based bullying intervention and prevention programs can be effective in reducing both bullying perpetration and victimization, although the effect is, overall, modest.

The effectiveness of antibullying programs is an important finding with implications for public health and educational policy. However, our review did identify that there are variations in the effectiveness of intervention programs. Future research is needed to explore the reasons for these variations.

1.6. How up‐to‐date is this review?

This report forms an update of an earlier review (Farrington & Ttofi,  2009 ). The review authors searched for studies published up to December 2016.

2. BACKGROUND

Bullying first emerged as an important topic of research in the 1980s, following the tragic suicides of young boys in Norway, the reason for which was attributed to bullying victimization (Olweus,  1993 ). Today, this form of aggressive behavior remains a prevalent problem among young people globally. For example, a recent meta‐analysis of 80 international studies discovered prevalence levels of 34.5% and 36% for bullying perpetration and bullying victimization respectively (Modecki et al.,  2014 ).

Notably, bullying is a matter of public health, impacting the life outcomes of both bullies and victims, in varying ways (Arseneault et al.,  2010 ; Masiello & Schroeder,  2014 ; Ttofi et al.,  2012 ). Given its long‐term effects, it is imperative that effective intervention efforts are put in place in order to alleviate this troubling school phenomenon (Ttofi,  2015 ).

2.1. Defining school bullying

In order to adequately determine which interventions will effectively reduce bullying behaviors, it is important that researchers and educators start by accurately assessing the prevalence of involvement in school bullying (Swearer et al.,  2010 ). There remains some degree of disagreement in relation to definitive cut‐off points for involvement in bullying (Solberg & Olweus,  2003 ; Swearer et al.,  2010 ) and methods utilized for the assessment of bullying (Smith et al.,  2002 ; Swearer et al.,  2010 ). However, there is better agreement in regard to the defining criteria for school bullying.

Prominent researchers in the field have defined bullying as any aggressive behavior that incorporates three core elements, namely: (1) an intention to harm, (2) repetitive in nature, and (3) a clear power imbalance between perpetration and victim (Centers for Disease Control and Prevention,  2014 ; Farrington,  1993 ; Olweus,  1993 ). In other words, bullies are individuals who intend to cause harm to their victims through their actions, over a long period of time. Furthermore, victims of bullying are typically less powerful than bullies, or groups of bullies, and feel that they cannot easily defend themselves. This may be due to a physical or social power imbalance.

There are many forms of bullying, for example, school‐bullying, workplace bullying, sibling bullying and, most recently, cyberbullying. The present review is concerned only with face‐to‐face school‐bullying, namely, bullying that occurs in schools between individuals, usually aged between 4 and 18 years old. In the school context, bullying is a complex social phenomenon, that often does not happen between the bully and victim in isolation (Salmivalli,  2010 ). For example, individuals can be involved in bullying, not only as bullies, victims, or bully‐victims, but also as bystanders, defenders, or reinforcers (Zych et al.,  2017 ).

Cyberbullying is another form of aggressive behaviors that may occur within a school community, and previous research has found a significant overlap between offline (i.e., school‐bullying or face‐to‐face bullying) and online bullying (Baldry et al.,  2017 ). There is currently very little information about the effectiveness of intervention programs designed to reduce cyberbullying or whether school‐based programs that also target face‐to‐face bullying can impact online bullying concurrently.

2.2. The importance of addressing school bullying

School‐bullying is a strong risk marker for several negative behavioral, health, social, and/or emotional problems. A recent comprehensive review of systematic reviews highlighted that the impact of school‐bullying can occur concurrently with perpetration and/or victimization, but also later in life (Zych et al.,  2015 ). Previous studies have found that bullying victimization is often followed by negative mental health outcomes such as: increased suicidal ideation (e.g., Holt et al.,  2015 ); generalized or social anxiety, low self‐esteem and loneliness (e.g., Hawker & Boulton,  2000 ); psychotic symptoms (e.g., van Dam et al.,  2012 ); depression (e.g., Ttofi et al.,  2011a ,  2011b ); sleeping problems (Geel et al.,  2016 ); and other psychosomatic symptoms (Gini & Pozzoli,  2013 ).

Bullying perpetration, on the other hand, has been linked to several negative outcomes such as: suicidal ideation and suicidal attempts (Holt et al.,  2015 ); weapon carrying (Valdebenito et al.,  2018 ); drug use (Ttofi et al.,  2016 ); and violence and offending in later life (Ttofi et al.,  2011b ,  2012 ). Although involvement in school bullying is not necessarily a causal factor for undesirable life outcomes, research has found that there is an apparent association. It may be the case that the experience of school bullying functions as a stepping stone toward undesirable life outcomes (Arseneault et al.,  2010 ).

Moreover, involvement in school bullying, as either a bully or a victim, has been found to correlate with factors such as low academic achievement (Strøm et al.,  2013 ), truancy from school (Gastic,  2008 ), and drug use (Valdebenito et al.,  2015 ). Such factors are common risk factors for youth offending and delinquency (Farrington & Welsh,  2008 ). Therefore, a bullying prevention program could serve as a crime prevention program, as well as a form of promoting public health.

3. OBJECTIVES

It is clear that school bullying is an important target for effective intervention and prevention. Bullying is an ethical problem as well as a developmental one: targeting school bullying facilitates the process of optimal psychological development but it also addresses the question of human rights, especially the rights of the child (Sercombe & Donnelly,  2013 ). The aim of this paper is to provide an up‐to‐date systematic and meta‐analytical exploration of the effectiveness of school‐based antibullying programs. As such, the present report updates an earlier systematic and meta‐analytic review (Farrington & Ttofi, 2009 ; Ttofi & Farrington,  2011 ), by including evidence from an earlier report, and all available evaluations of antibullying programs since 2009.

It is hoped that this new evidence base will assist policy‐makers and practitioners working in the field of bullying prevention. Farrington and Ttofi's ( 2009 ) review concluded that school‐based antibullying programs are effective in reducing both bullying perpetration (OR = 1.36; 95% CI: 1.26–1.47; z  = 7.86; p  < .0001) and bullying victimization (OR = 1.29; 95% CI: 1.18–1.42; z  = 5.61; p  < .0001). Their review had a major impact on the field of bullying intervention and prevention, and in the 9 years that have passed since its publication there has been a wealth of new research.

Therefore, the aim of the present report is to conduct systematic searches for new evaluations of antibullying programs, and also update earlier analysis by including their 53 evaluations.

The initial stage of any meta‐analysis involves conducting a thorough and systematic search of all the existing and relevant literature (Lipsey & Wilson,  2001 ; Littell et al.,  2008 ). Using predetermined keywords and strict inclusion/exclusion criteria, a systematic review aims to identify, screen, appraise, and synthesize all relevant empirical studies (Zych et al.,  2017 ). In this way, systematic bias is avoided.

4.1. Inclusion and exclusion criteria

To be included in the present systematic review, a set of strict inclusion and exclusion criteria were employed to guide searches. These criteria were identical to those used in the previous meta‐analysis (Farrington & Ttofi,  2009 ). Specifically, to be included, primary studies must:

• (1) Describe an evaluation of a school‐based antibullying program implemented with school‐age participants (depending on the site of evaluation, ages may vary between 4 and 18 years of age);
• (2) Utilize an operational definition of school‐bullying that coincides with existing definitions (e.g., CDC,  2014 ; Farrington,  1993 ; Olweus,  1993 );
• (3) Measure school‐bullying perpetration and/or victimization using quantitative measures, such as, self‐, peer‐, or teacher‐report questionnaires; and
• (4) Use an experimental or quasi‐experimental design, with one group receiving the intervention and another (control group) not receiving the intervention. Nonrandomized studies had to measure outcomes before and after the intervention.

As a result, the present systematic review excludes studies that evaluate the effectiveness of intervention programs targeting alternative forms of bullying, such as cyber‐bullying (e.g., Del Rey et al.,  2015 ), general aggression (e.g., Leff et al.,  2010 ), and school violence (e.g., Giesbrecht et al.,  2011 ). Other studies were excluded because they measured bullying‐related nonbehavioral outcomes, for example, “attitudes towards bullying” (e.g., Earhart,  2011 ), or coping strategies for dealing with victimization (e.g., Watson et al.,  2010 ).

In addition, studies conducted with special needs, delinquent, or psychiatric populations were excluded (e.g., Espelage et al.,  2015 ), so that results could be generalizable to the wider mainstream school population. Studies using qualitative measures of effectiveness, such as participant perceptions of the effectiveness of the program (e.g., Fletcher et al.,  2015 ), were also excluded.

4.2. Searches 1

In order to identify potentially includable studies, Boolean searches were conducted using multiple combinations of the following keywords: bully*; victim*; bully‐victim; school; intervention; prevention; program*; evaluation; effect*; and anti‐bullying . A full description of the syntax used is provided in Appendix A.

Searches were conducted on several online databases, including, but not limited to: Web of Science, 2 PsychINFO, EMBASE, DARE, ERIC, and Scopus. Google scholar ( www.scholar.google.co.uk ) was also searched. A full list of databases searched is provided in Table  1 . EBSCOhost was used as a platform to search multiple databases concurrently and such databases are indicated in Table  1 .

Online platforms and databases manually searched

Note: EBSCOhost was used as a platform to search multiple databases concurrently. Such databases are marked with an *.

Databases of unpublished reports (e.g., ProQuest Dissertations and Theses Solutions) were also searched to include gray literature in our review. This should help to minimize potential publication bias linked to larger or significant effect sizes (Easterbrook et al.,  1991 ; McAuley et al.,  2000 ). In addition, evaluation studies included by previous systematic reviews were scanned, based on the name of each program, for additional‐updated evaluation results (i.e., Cantone et al.,  2015 ; Chalamandaris & Piette,  2015 ; Evans et al.,  2014 ; Jiménez‐Barbero et al.,  2012 ,  2016 ).

Studies included in the previous review (Farrington & Ttofi,  2009 ; Ttofi & Farrington,  2011 ), were also included in the present systematic review. Searches for the present review were conducted up to the end of December 2016, 3 for empirical studies published during and since 2009.

4.3. Screening

Our searches of the literature produced approximately 19,877 reports that were screened for eligibility. Based on the title and abstract, a total of 474 primary studies were identified as relevant, were obtained and subjected to further screening. Studies were allocated to six categories based on their relevance to the current meta‐analysis. A description of each category is provided in Table  2 . Screening was undertaken by the first author (H. G.), under the supervision of the second author (M. T.), in a collaborative format. H. G. reviewed eligible studies, and any queries were settled in discussion with M. T.

Relevance scale categories used in screening

The initial wave of screening excluded 258 of these primary studies. At this stage, studies were excluded because they: (1) did not evaluate a specific antibullying program (Category 1; n  = 107); (2) reviewed several different antibullying programs (Category 2; n  = 108); or (3) did not report empirical quantitative data from an evaluation of a specific antibullying program (Category 3; n  = 43).

A second wave of screening excluded a further 133 studies (Category 4; see Table  3 ). Primary studies were excluded at this stage because they: (1) reported irrelevant outcomes; (2) did not have an adequate control group; or (3) did not meet specified methodological criteria. The screening process is described in detail in Figure  1 . In total, 83 studies published since 2009 were included in our updated systematic review (Category 5).

Descriptions of category four studies

Screening of studies

In addition, five studies were identified during searches conducted for a meta‐analytical review of cyberbullying prevention programs (Gaffney et al.,  2018 ). These studies were missed during systematic searches for the current review (i.e., Kaljee et al.,  2017 ; Ortega‐Ruiz et al.,  2012 ; Ostrov et al.,  2015 ; Silva et al.,  2016 ; Solomontos‐Kountouri et al.,  2016 ). One of these studies (i.e., Kaljee et al.,  2017 ) has a publication date outside of the range of our searches. However, it was included because it was available online in 2016.

To provide the most up‐to‐date analysis of school‐based bullying prevention and intervention programs, therefore, a total of 88 newly identified studies are included in the present systematic review.

5. DATA EXTRACTION

After identifying studies eligible for inclusion in the present systematic and meta‐analytical review detailed information about the antibullying programs, sample involved, and evaluation design were extracted from primary studies. The following chapter outlines the coding framework applied in greater detail.

Table  4 also outlines each piece of information extracted. Information was extracted from primary studies under four main headings: (1) Descriptives, (2) Design, (3) Program, and (4) Outcomes. Additionally, the following section outlines information extracted from primary studies in order to create a risk of bias index. Table  5 outlines the items utilized to assess risk of bias for each of the methodological designs included in the present report. Details of the risk of bias results for each study is provided in Appendix B.

Coding framework

Abbreviations: BA/EC, quasi‐experiments with before and after measures of bullying (nonrandomized); exp, experimental group; OBPP, Olweus Bullying Prevention Program; RCT, randomized controlled trial.

Risk of bias tool

Abbreviations: AC, age cohort design; BA/EC, quasi‐experimental design with before and after measures of bullying; RCT, randomized controlled trial.

This procedure was carried out by the first author in consultation with the second and third authors. 4 There were a number of studies from the previous Campbell Collaboration report (i.e., Farrington & Ttofi,  2009 ) for which full texts were unavailable and thus, were excluded from several of the moderator analyses.

5.1. Descriptive

Various pieces of descriptive information were extracted from each of the 100 evaluations included in the present report. Information specific to the evaluation, such as the location or the start/end date, were recorded along with detailed information concerning the sample.

The total sample size and also the n of the relevant experimental and control groups were recorded. Age was extracted in two ways. First, where studies reported the mean age, or the age range (i.e., 8–10 years old) of participants this was recorded. Second, some studies did not report the age in years of participants, but we were able to record the school grade of included samples (i.e., Grades 4–6). Where reported, the % of females and males included in the sample was extracted.

We also coded descriptive information about the publication of the evaluation. Specifically, the type of publication and the publication year was recorded. The former represents a categorical moderator reflected whether or not the evaluation was published via the following channels, in order of hypothesized negative correlation with bias: (1) peer‐reviewed journal article; (2) chapter in an edited book/book; (3) governmental report or similar; (4) correspondence; and (5) unpublished masters or doctoral theses.

Correspondence was included to reflect data obtained from multiple evaluations of the Olweus Bullying Prevention Program (OBPP) sent to the second (M. M. T.) and third (D. P. F.) authors in preparation of their earlier Campbell review. Where evaluation data had been published in multiple formats, we favored the category associated with the least potential bias. For example, Domino ( 2011 ) reported the results of an evaluation of Take the LEAD program in a doctoral dissertation, but later published these results in a peer‐reviewed journal (i.e., Domino,  2013 ). In this scenario, the included study was coded as “article.”

5.2. Design

Included studies were further categorized according to several aspects of the research design used. We coded information regarding both the measures (i.e., instruments to measure bullying behaviors) and research design.

In relation to measurements of bullying, we recorded the timeframe (i.e., past 3 months or “ever”) in which participants were asked to report on experiences of bullying, the type of report used (i.e., self‐, peer‐, or teacher‐report), and data collection points (i.e., baseline, postintervention, 3‐month follow‐up, etc.). We also noted whether the measure was a continuous scale or a global item and whether bullying perpetration, victimization, or both, outcomes were measured.

As for the research design, we recorded information regarding the unit of allocation (or unit of randomization for RCTs; see below), the number of “clusters” included, whether groups were matched at baseline, and the number of experimental or control groups. For example, Elledge et al. ( 2010 ) included multiple control groups: matched controls and nonmatched controls.

Information about the evaluation methodology was also extracted from primary reports. The types of evaluation methodologies included in the present report are now described in further detail.

5.2.1. Evaluation methodology

In order to optimize the comparability of effect sizes, primary studies included in a meta‐analysis should use the same, or at least conceptually similar, research designs (Wilson,  2010 ). Following Farrington and Ttofi's ( 2009 ) criteria, we searched for evaluations using any of the following four research designs:

• (1) Randomized controlled trials (RCTs);
• (2) Before‐after/quasi‐experimental‐control designs (BA/EC);
• (3) Other quasi‐experimental designs; and
• (4) Age cohort designs.

Each of these methodologies varied on four key elements: as randomization of participants (or clusters of participants); use of experimental and control groups; and administration of quantitative bullying measures before and after intervention.

For example, all studies coded as RCT had to include random assignment to experimental conditions (i.e., intervention and control groups) but did not have to use before and after measures of bullying outcomes. RCTs are considered to be the “gold standard” of experimental evaluations (Weisburd et al.,  2001 ). Random assignment of a large number of units is used as a way in which evaluators can also randomize possible confounding variables between groups. As a result, we can infer that any observed differences result from the experimental manipulation (Farrington,  1983 ). The assumption is that randomization ensures that both observed and unobserved variables that may impact the results of an evaluation are also randomly distributed between groups. However, problems may arise if the unit‐of‐allocation, the unit‐of‐randomization, and the unit‐of‐analysis do not align.

Before‐after/quasi‐experimental‐control (BA/EC) designs, are conceptually similar to RCTs, but they do not involve random assignment to experimental conditions. Instead, participants or clusters of participants may be assigned to the intervention or control group on a self‐selected basis (e.g., Menesini et al.,  2012 ), for convenience (e.g., Sapouna et al.,  2010 ), or based on a greater need for intervention (e.g., Losey,  2009 ). Thus, BA/EC designs may be subject to selection biases (Farrington & Petrosino,  2001 ) that may reduce the validity of the results. These can be controlled if outcomes are measured before and after the intervention. Studies coded as BA/EC in the present report all used experimental and control groups but did not randomly assign participants to conditions. They also had to measure bullying outcomes before and after implementation of the intervention.

In contrast, studies categorized in the current review as using “other quasi‐experimental” designs utilized experimental and control conditions, without random assignment, but did not measure bullying behaviors before the intervention. Bullying outcomes were only measured after the implementation of an intervention in these studies. Therefore, selection bias is may be a threat to the internal validity of the results in such designs, which could have possibly attributed to pre‐existing differences between the groups (Farrington, 2003 ). For this reason, a decision was made to omit these designs from this updated meta‐analysis. Thus, relevant evaluations identified in the earlier Campbell Review and any new evaluations (since 2009) using this methodological design were excluded from the new meta‐analyses (see later).

In an age cohort design, students of a particular age X are initially assessed in the 1st year and serve as the control group for the evaluation of an intervention. Then, all students receive the intervention, and different students of the same age X (in the same school, in the 2nd year) serve as the experimental group (see Kärnä et al.,  2013 ). This design, which is largely used in evaluations of the OBPP, deals with some selection effects, since it ensures that experimental and control children are matched on age and school, and it deals with some threats to internal validity (e.g., ageing and maturation). However, this design may be influenced by period and testing effects, and the experimental and control groups may differ on other uncontrolled variables.

Studies employing RCTs, BA/EC, and age cohort designs were included in the present systematic and meta‐analytic review. Because of the potential threat to internal validity, we excluded studies ( n  = 9) in the other quasi‐experimental design category because they are poorly controlled and vulnerable to selection effects. Additionally, the four studies included in the earlier review that used an “other quasi‐experimental” design were excluded from the present systematic review.

5.3. Program

Using a socio‐ecological systems theory framework (Bronfenbrenner, 1979 ) and the previous meta‐analysis (i.e., Farrington & Ttofi,  2009 ) as guidelines, information about the specific intervention program was recorded. General details about the intervention, such as the name of the program (where relevant) and the aim of the intervention (e.g., Silva et al.,  2016 ) were noted along with more detailed information about the antibullying programs.

Intervention components at multiple levels of the socio‐ecological model (i.e., individual, peer, parent, and teacher, etc.) were recorded, such as work with peers, parental involvement, teacher training and whole‐school‐approach. Therefore, a brief description of each antibullying program based on this information is provided in Table  6 .

Systematic review results

In addition to specific program elements included in interventions, we also coded for possible sources of bias in evaluations and intervention development. Conflict of interest (COI) has previously been reported to impact evaluation results of many interventions and is a growing area of interest (COI; Eisner & Humphreys,  2012 ) with studies identified as having higher COI associated with larger overall effect sizes. Eisner and Humphreys outline many other possible sources of COI, such as financial gain to the evaluator, but this information was difficult to obtain for antibullying programs. Thus, a simple indication of potential COI was utilized.

We primarily focused on the overlap between individuals included as author/coauthor on the evaluation study, is also included on previous evaluations of the same program (e.g., NoTrap!; Menesini et al.,  2012 ; Palladino et al.,  2012 ,  2016 ), or is in fact referenced as the developer of that particular program (e.g., Tsiantis et al.,  2013 ). If no reference to a publication relating to the specific program was included, we concluded that the author had developed the program, and thus, the evaluation was deemed high risk.

Program specificity refers to whether the intervention program was specifically targeting bullying outcomes, or if many other outcomes were also included. Targeted programs are suggested to be more effective than generalized programs that aim to reduce many different behaviors in one intervention. Highly specific programs (i.e., those that only included bullying outcomes and very few others) were coded as “high.” Thus, programs that were less specific and included many other outcomes in addition to bullying measures were considered “low.” A third category was created (i.e., “medium”) to include studies that did multiple other outcomes in addition to bullying outcomes, but these additional variables were bullying‐related.

5.4. Outcomes

We also extracted several pieces of statistical information from primary studies that was required for the estimation of effect sizes. Statistics for bullying behaviors, for example, means and standard deviations or sample sizes and percentage of bullies and/or victims, were extracted for experimental and control groups at baseline and immediately postintervention timepoints.

We also coded bullying data for additional follow‐up timepoints where this information was reported by primary studies. Data was extracted and recorded separately for independent samples (i.e., female and male, Palladino et al.,  2016 ; older and younger, Baldry & Farrington, 2001) and different measures. For example, data for both self‐ and peer‐report measures were extracted from Beery and Hunt (2009) and for different forms of bullying (e.g., Frey et al.,  2005 ).

5.5. Risk of bias

As per the Campbell Collaboration reporting guidelines, a risk of bias index was created for the purpose of the present report. The EPOC tool was utilized to assess the risk category of each study on several items relating to the methodological quality of evaluations. Following earlier Campbell review (e.g., Valdebenito et al.,  2018 ) this tool was also used for nonrandomized studies as other risk of bias measurement instruments were considered inappropriate for nonscientific or medical trials.

The following section describes the procedure for addressing risk of bias in the present meta‐analysis. Each primary evaluation was measured on the following items: (1) allocation sequence (AS); (2) Allocation concealment (AC); (3) Baseline equivalence on outcomes (BE); (4) Baseline equivalence on participant characteristics (BC); (5) Incomplete outcome data (ID); (6) Contamination protection (CP); and (7) Selective outcome reporting (SOR). The applicability of these categories for each of the methodological designs included in the present report is outlined in Table  5 . Each study was categorized as being high, low, or unclear (if insufficient information was available) risk on each of these EPOC items.

6. INCLUDED INTERVENTIONS

In total, 67 different school‐based antibullying programs were evaluated by primary studies included in our updated meta‐analysis. Descriptions of each of these interventions is provided in the following section of this report. These narrative reviews of included antibullying programs are based on the best available information provided by the primary studies. Twenty‐one of the evaluated antibullying programs were included (only) in the previous meta‐analysis (Farrington & Ttofi,  2009 ). A number of popular school‐based antibullying programs (n = 7; i.e., Bully Proofing Your School [BPYS], Friendly Schools, KiVa, OBPP, Steps to Respect, ViSC, and Youth Matters) had been re‐evaluated or additional publications since 2009. Hence, the majority of programs evaluated in our updated meta‐analysis ( n  = 40) are new bullying prevention and intervention programs.

The following sections provides detailed summaries of each antibullying program included in our systematic review. Descriptions marked with an * were taken from the previous review (Farrington & Ttofi,  2009 ). To provide the reader with a detailed overview of existing antibullying programs studies subsequently excluded from the meta‐analysis are also included here.

6.1. *Antibullying intervention in Australian secondary schools

This antibullying intervention consisted of several activities that aimed to increase awareness and identification of bullying, to promote empathy for targets of bullying and to provide students with strategies to cope with bullying (Hunt,  2007 , p. 22). The intervention was based on an educational antibullying program, which was delivered by teachers. There was no specific training for teachers. Information about bullying was provided at parent and teacher meetings. Teacher meetings were held in conjunction with regular staff meetings while parent meetings were held after hours. A summary of the information covered at parent meetings was also published in the school newsletter in an attempt to target the wider parent population. Finally, the program includes a 2‐h classroom‐based discussion of bullying (offered by teachers) using activities from an antibullying workbook written by Murphy and Lewers ( 2000 ).

6.2. Anti‐Bullying Pledge Scheme (ABPS)

The ABPS describes a number of local antibullying schemes implemented in UK schools as a result of government recommendations and guidance (Pryce & Frederickson,  2013 ). Schools adopted a declaration of commitment, and intervention components followed a theoretical framework guided by the Theory of Planned Behavior (Ajzen,  1991 ).

The ABPS is a universal prevention program, that aims to reduce the prevalence of bullying perpetration and victimization in schools and increase students' perceptions of safety and support within the school environment (Pryce & Frederickson,  2013 ). Participating schools were assigned a facilitator, referred to as a “pledge supporter,” and a detailed intervention manual. The manual outlined the stages involved in implementing the ABPS program. The stages are as follows:

• Initial meeting with school management and the pledge supporter
• Intervention planning meeting
• School representatives make a declaration of commitment to the intervention
• Staff, student, and parent surveys are circulated
• Results from the surveys were collated and used to tailor intervention components to the individual schools' needs
• Ongoing visits and support from the pledge supporter throughout implementation.

6.3. *Be‐prox program

The Be‐Prox program was specifically designed to tackle bullying and victimization among kindergarten students. According to Alsaker and Valkanover ( 2001 , pp. 177–178), the somewhat higher adult‐children ratio, the interest of preschool teachers in socialization, the greater flexibility as to scheduling and teaching, and the admiration of many preschoolers for their teachers are ideal conditions for the implementation of preventive programs against bully/victim problems. The basic principle of Be‐Prox was to enhance preschool teachers' capacity to handle bully/victim problems (Alsaker,  2004 , p. 291). The program engaged teachers in an intensive focused supervision for approximately 4 months. Central features of Be‐Prox were the emphasis on group discussions, mutual support and co‐operation between consultants and teachers and between teachers and parents (Alsaker,  2004 , pp. 292–293).

The teacher training was provided in six steps (Alsaker,  2004 ; fig. 15.1, p. 292). Initially, teachers were given information about victimization (step 1) and the implications of this information was discussed (step 2). During the third step, specific implementation tasks were introduced and the teachers worked in groups in preparation for the practical implementation (step 4). After this preparation, teachers implemented specific preventive elements in the classroom (step 5) for a specific period of time. After that, teachers met and discussed their experiences of the implementation of the preventive measures (step 6).

In eight meetings over a 4‐month period, issues related to the prevention of bullying were addressed. The main purpose of the first meeting was sensitization. Teachers were asked to describe any possible bully/victim problems in their schools and were then given information about bullying and other types of aggressive behavior. They were also presented with the main principles of the program. The importance of contact between kindergarten teachers and children's parents was also emphasized and teachers were advised to consider the possibility of organizing a meeting with parents. In the second meeting, the importance of setting limits and rules to preschool children was discussed. Teachers were invited to elaborate some behavior codes in their classroom in collaboration with the children and to be ready to present them during the third meeting. Also, as a second homework task, teachers were asked to organize a parent meeting.

During the third meeting, teachers discussed their experiences of implementing classroom rules against bullying. The main focus of this meeting was the need for consistent teacher behavior, the difference between positive and negative sanctioning and the use of basic learning principles in the classroom. The main focus of the fourth session was on the role and responsibility of children who were not involved in bullying and of bystanders in the prevention of victimization. Teachers were asked to draw some kind of personality profiles of passive and aggressive victims and of bullies and to present them to the rest of the group. After this task, teachers were presented with research findings regarding the characteristics of children who were or were not involved in bullying. As a homework task for the next meeting, teachers were asked to systematically observe noninvolved children and to develop some means of involving them in the prevention of victimization.

During the fifth meeting, research‐based information about motor development and body awareness among preschool children was presented to teachers. A discussion between teachers and program researchers of children's self‐perceptions of strength, of peers' perceptions of strengths of victims of bullies, and other motor characteristics of children, aimed to yield important insights. The overall discussion and exchange of information among teachers aimed to promote teachers' understanding about how to change these perceptions within the classroom setting. Specific goals to be achieved within the classroom were clearly set, such as training in empathy and body awareness among children, participation and involvement of noninvolved children and talks with all the children about the situation in their kindergarten. During the sixth meeting, time was given to reflect on the goals formulated at the beginning of the prevention program. Teachers were also given time to discuss their experiences with implementing the goals of the fifth meeting within the classroom settings. The last two meetings followed a similar format, with time given for reflection on goals achieved, problems dealt with, and an overall evaluation of the program.

6.4. *Befriending intervention

Befriending intervention was an antibullying program that relied mainly on a peer support model. The overall aims of the program were: (a) to reduce bullying episodes through developing in bullies an awareness of their own and others' behavior; (b) to enhance children's capacity to offer support to the victims of bullying; (c) to enhance responsibility and involvement on the part of bystanders; and (d) to improve the quality of interpersonal relationships in the class group (Menesini et al.,  2003 , p. 1).

The antibullying intervention was offered in five steps (Menesini et al.,  2003 , p. 5). During the first phase, which targeted the class level (class intervention), several activities were offered aiming to increase children's awareness of prosocial and helping behaviors and to promote positive attitudes toward others. Through work at the class level, the school authorities sensitized and prepared the whole school population for the new service that the school unit was about to implement. In this way, another goal was achieved, namely developing values and attitudes toward “peer support activities” in the whole school population.

During the second phase of the program, the “peer supporters” were selected. Approximately three to four supporters were allocated in each classroom and were selected based on a combination of techniques, such as self‐ and peer‐nominations. These children were then trained in special full‐day sessions or in regular meetings during school time (phase three) so that they knew how to deal with other children and how to facilitate interactions among other children. Teachers and other professionals (psychologists and social workers) took part in these sessions as well. The overall aim of this phase of the antibullying program was to help peer supporters to enhance their listening and communication skills since they would be the mediators in the interactions among children.

During the fourth phase of the program, peer supporters worked in their classes with the assistance and close monitoring of their teachers. The teachers in each class organized “circle meetings” during which the needs of specific children involved in bullying (target children) were identified. Target children were contacted and, after their consent and cooperation, were offered help by the peer supporters. Peer supporters were not only assigned to specific tasks involving the target children but were also supervised by the teachers so that they were given constant feedback on their on‐going work in the class.

During the final phase of the Befriending Intervention, the leading group of peer supporters were involved in training other children in the class, so that more children could be involved in the program (in the transmission of training and passing on the roles).

6.5. *Behavioral program for bullying boys

This program targeted male youth, from a low socio‐economic area, predominately inhabited by individuals of color, involved in bullying. The program was based on the findings of an in‐depth needs assessment within three schools and targeted a specific number of male students aged sixteen who (based on the results of the questionnaire that had been administered) were “considered to be a serious threat to the harmonious functioning of everyday school life” (Meyer & Lesch,  2000 , p. 59). The theoretical basis of the program could be found in the Social Interactional Model for the development of aggression (Meyer & Lesch,  2000 , p. 61) and involved a behavioral approach for tackling the problem of bullying. The program was implemented by psychology students for ten nonconsecutive weeks, with 20‐h‐long sessions held twice weekly at the school, during school hours.

The components of the 17‐session behavioral program included homework tasks, modeling, self‐observation, role‐plays, and a token economy system for reinforcing positive behaviors. According to the program designers “the chief contingency for behavioral change was the token economy system, using Wonderland Games tokens, chocolates and cinema tickets as reward for non‐bullying behavior” (Meyer & Lesch,  2000 , p. 62). Each participant was monitored by himself and by a “buddy” who was selected in each session prior to the monitoring. Each session included an opportunity for feedback on the students' progress in the week, a discussion of a relevant applied topic, role‐playing, games, and drawing. The program designers pointed out the limitations of the intervention strategy. As they indicate (Meyer & Lesch,  2000 , p. 67) “the program was too short and structured to address the issues that were disclosed in sessions, as the severity of the nature of the aggression in the schools and vast social problems was seriously underestimated.”

6.6. Beyond the Hurt

Sutherland ( 2010 ) implemented the Beyond the Hurt program, a peer‐led school‐based bullying intervention and prevention program, developed by the Red Cross. Beyond the Hurt is a high school program and emphasizes education, prevention and intervention to reduce prevalence of bullying perpetration and victimization. Sutherland ( 2010 , p. 84) describes the four key components of the intervention: (1) education and training of peer facilitators, (2) in‐class presentations given by peer facilitators, (3) teacher workshops, and (4) online training material for teachers and community members.

This peer‐led program trains and educates select peer facilitators, who become the implementers of the intervention program within participating schools. These students are guided by a teacher and Red Cross professional throughout training and implementation of class presentations highlighting several bullying‐related issues. The overarching aim of the Beyond the Hurt program is to create a positive school and class climate in which students are encouraged to develop and maintain healthy prosocial relationships, and bullying perpetration and victimization are not supported. The program aims to promote antibullying attitudes among participants and encourage empathy and prosocial support for victims of bullying.

6.7. *Bulli and Pupe

Bulli and Pupe was an intervention program concerned with bullying and family violence. The program, developed by Baldry (2001), was “directed towards the individual and peer group, and aimed to enhance awareness about violence and its negative effects” (Baldry & Farrington,  2004 , p. 3). The intervention package consisted of three videos and a booklet divided into three parts; each video was linked to one part of the booklet. Each part of the booklet was meant to take the form of an interactive lesson where professionals, experienced in school and juvenile processes, discussed three issues according to the structure of the manual.

The first part of the booklet, entitled “Bullying among peers,” emphasized teen violence among peers. The booklet presented vignettes and graphics that reported research findings on bullying in an attempt to raise students' awareness of this issue. The corresponding video showed teenagers talking about bullying based on their own experiences and judgments. The second part of the booklet, entitled “Children witnessing domestic violence,” analyzed the effects of domestic violence on children and the repercussions for school achievement and peer relations. In the accompanying video, children in a shelter for battered women were presented, talking about their personal experiences and emotions. Finally, the third part of the booklet, entitled “Cycle of violence,” dealt with the long‐term effects of violence on adults who were victims of violence in their childhood. The corresponding video consisted of an interview conducted with a 19‐year old boy who had a violent father.

The program was in the first place delivered in 3 days by experts who, together with teachers, discussed about bullying, read the booklet and analyzed its content. The program was taken over by teachers who once a week created a facilitation group and allowed children to discuss any problems they encountered with their peers. The program was more effective with secondary students because it required its participants to have good interpersonal and cognitive skills (Baldry & Farrington,  2004 , p. 4).

6.8. The Bully Prevention Challenge Course Curriculum (BPCCC)

Battey ( 2009 ) implemented the BPCCC (Haggas,  2006 ) to students over two 45 min classes, on 4 days of one school week. The program was implemented by trained facilitators, whom included the schools' physical education/health teacher. The program commenced by providing participants with name tags and organizing some warm‐up physical activities. Next, the physical education/health teacher provided participants with information about bullying, such as, identifying and addressing bullying, who to talk to and where to seek support. Subsequent group discussions focused on empathy and understanding each other's differences. Audience participation activities also required the students to engage to represent the number of students whom had been a victim or bully.

6.9. Bully Proofing Your School

“Bully‐Proofing Your School” was a comprehensive, school‐based intervention program for the prevention of bullying (Menard & Grotpeter,  2014 ; Menard et al.,  2008 ; Toner,  2010 ). The program involved three major components: (1) heightened awareness of the problem of bullying, involving a questionnaire to measure the extent of bullying and the creation of classroom rules related to zero tolerance for bullying; (2) teaching students protective skills for dealing with bullying, resistance to victimization and providing assistance to potential victims by teaching assertiveness skills; and (3) creation of a positive school climate where students were encouraged to work as positive and supportive bystanders (Menard et al.,  2008 , p. 7).

The primary targets of BPYS were elementary and middle school students. School staff were involved as both secondary targets of intervention (since changes in their behavior was a requirement for the construction of a positive antibullying school environment) and as agents delivering the intervention to students. Teachers were given information and strategies to help them recognize bullying incidents among their students and how to effectively deal with these behaviors (Menard & Grotpeter,  2014 ).

The intervention in the classes consisted of a classroom curriculum, which included seven sessions of approximately 30–40 min. Each session was delivered by a teacher or by mental health staff. After completion of the classroom curriculum materials, teachers were encouraged to hold weekly classroom meetings during which students could be helped to reflect on their behaviors. Parents were offered information through newsletters. Individual parents of students involved in bullying as either perpetrators or victims were given consultation (Menard & Grotpeter,  2014 ).

6.10. Chinese antibullying intervention

Ju et al. ( 2009 ) implemented an antibullying program in a Chinese primary school employing an action research framework. There were two main aims of this intervention program. First, the program aimed to reduce bullying perpetration and victimization both on students' way to, and from, school. Second, the study aimed to investigate practical intervention elements that could be applied nationwide to Chinese primary school children (Ju et al.,  2009 ).

The initial step in this intervention was the training of teachers on the fundamental principles of action research. This training program targeted the following components of educational research: (1) research methodology in education; (2) knowledge of school bullying; (3) components of action research; and (4) intervention skills, such as brainstorming and role‐playing. Second, a 5‐week intervention program was designed and implemented by teachers in classrooms. Components that targeted both victims and bullies specifically were also incorporated into the intervention.

6.11. The Confident Kids program

The Confident Kids program is an antibullying intervention designed for early adolescent males who were experiencing anxiety as a result of being bullied at school (Berry & Hunt,  2009 ). The foundations of the program lie in cognitive‐behavioral therapy, employing both anxiety management techniques and antibullying elements. Based on the “Cool Kids Program” (Lyneham et al., 2003), this intervention program aims to reduce bullying victimization by targeting factors that increase the likelihood of victimization. Therefore, this program focuses primarily on issues such as: self‐esteem, coping strategies; social skills; emotional regulation; and internalizing behaviors.

The program was implemented over a period of 8 weeks, and included student and parent involvement. Students participated in weekly group sessions led by a team of assistant and qualified clinical psychologists. These sessions incorporated a combination of tasks including: skill demonstration; role‐playing; and group discussion. Homework was allocated after each session and participants were encouraged to apply skills acquired in real‐life settings between each session.

Sessions covered a variety of issues, including both cognitive‐behavioral anxiety management techniques and antibullying information. Seven core sessions focused on the following topics: psycho‐education; cognitive restructuring (2 sessions); graded exposure; adaptive coping strategies; improving social skills; and self‐esteem. A final session targeted relapse prevention and provided a general overview of the skills learned throughout the program. Parents participated in sessions that ran parallel to the student program. Group discussions targeted the strategies being taught to student participants and also possible parent factors that could influence effectiveness of intervention for their children, for example, parental anxiety.

6.12. Cyberprogram 2.0

Cyberprogram 2.0 is a cyberbullying intervention program that also incorporates elements on school bullying (Garaigordobil & Martínez‐Valderrey,  2015 ). The intervention is delivered over 19 sessions, and outlines the following four main goals:

• To outline and conceptualize bullying and cyberbullying, including identifying the different roles involved (e.g., bullies, victims, and bystanders).
• To illustrate the consequences of bullying and cyberbullying for all those involved
• To develop coping strategies in order to reduce bullying and cyberbullying behaviors.
• Developing positive social and emotional skills, such as empathy, active listening, anger management, conflict resolution strategies, and diversity tolerance.

A wide range of activities and techniques are used, such as, role‐playing, brainstorming, case studies, and guided discussion. The Cyberprogram 2.0 intervention followed a specific methodological framework, employing four key components for implementation. They are as follows: (1) inter‐session constancy: intervention was delivered in weekly 1‐h sessions; (2) spatial‐temporal constancy: intervention was delivered in the same place and at the same time each week; (3) constancy of adult facilitator: intervention was implemented by the same adult, who same psycho‐pedagogical training, each week; and (4) constancy in the session structure: sessions being with group instruction and activities. There is then a following reflection phase that is led by the adult.

6.13. Daphne III

Daphne III was an international antibullying initiative implemented and developed in association with numerous organizations. In this study (Papacosta et al., 2014), school antibullying programs were coordinated in Cyprus by the Association for the Psychosocial Health of Children and Adolescents (APHCA). Other influential “partners” included the Cyprus Ministry of Health, mental health services, Department of Child and Adolescent Psychiatry, Ministry of Education and Culture, and Educational Psychology services. Organizations from other European countries included: Child Line [ Vsi Vaiku Linija ], in Lithuania, and Nicolaus Copericus University, in Poland, were also involved.

The overarching aim of this initiative was to educate 5th and 6th grade primary school students about bullying, and the many different forms it can take (Papacosta et al., 2014). Teachers implemented the program in their classrooms, and were trained by psychology and mental health professionals. There were eleven workshops involved in the program that followed a structured curriculum manual. This manual also provided schools with suggestions and recommendations on ways in with they could prevent, and intervene in, bullying situations.

6.14. *Dare to Care: BPYS program

“Dare to Care; Bully Proofing Your School” was a modification of the “Bully Proofing Your School” program (Beran et al.,  2004 , p. 103), which in turn was modeled on the Olweus Program. This antibullying program placed emphasis on clinical support to victims and perpetrators of bullying in the form of individual and group counseling. It also enabled collaboration with community services. The essence of the program was to encourage accountability for creating solutions among all parties involved in the education system (Beran et al.,  2004 , p. 104).

The program included several steps. Program facilitators provided to school personnel information and training on issues related to bullying in schools (in a full‐day professional development workshop). This workshop aimed to ensure that the program principles would be reflected in the overall curriculum and would be sustained over time. Information was also given to parents. Then, students, parents and school staff collaborated in the development of a school antibullying policy. This policy had the aim of identifying caring and aggressive behaviors and consequences of those behaviors, but with a focus on reparation rather than punishment. The antibullying policy was posted throughout the school. Finally, the program involved the implementation, on behalf of the teachers, of a classroom curriculum that educated children about the nature of bullying and strategies to avoid victimization. The curriculum included discussion, role‐plays, artwork, books, videos and skits presented to school staff, parents, and other children.

6.15. Defeat Bullying

The Defeat Bullying program is a curriculum‐based antibullying program that was published by the National Society for prevention of Cruelty to Children (NSPCC, UK) in 2007 (Herrick,  2012 ). The program materials were available to download online, as part of a nationwide campaign to reduce bullying perpetration and victimization in UK schools. The overarching aim of the Defect Bullying program is to raise awareness and improve attitudes toward bullying, educate about bullying‐related feelings and emotions, and to develop effective intervention and conflict resolution strategies (Herrick,  2012 , p. 85). Based on social identity theory (Tajfel & Turner,  1979 ), the program aims to establish an in‐class antibullying norm, so that students will be encouraged to adopt this norm, and thus, reduce levels of bullying perpetration and victimization.

There are five key lessons implemented throughout the program, and each incorporates a range of individual, class and group activities (Herrick,  2012 ). The lessons cover the following five themes: (1) understanding attitudes and values toward bullying; (2) educating about the feelings that occur as a result of bullying; (3) embracing diversity; (4) safety awareness; and (5) encouraging bystanders to get involved in antibullying strategies. The available intervention materials were also reviewed by groups of teachers, and any necessary amendments were incorporated. For example, Herrick ( 2012 ) describes that following teacher discussion groups, homework assignments relating to each lesson were developed and implemented. Parents of participating students were also invited to attend an antibullying workshop led by the researcher.

6.16. *Dutch antibullying program

The antibullying initiative in the Netherlands was inspired by the Olweus program (Fekkes et al.,  2006 , p. 639). The program was specifically designed to tackle bullying behavior by involving teachers, parents and students. It offered a 2‐day training session for teachers in order to inform them about bullying behavior and to instruct them about how to deal with bullying incidents in schools. During the intervention period, teachers had access to the training staff for additional advice. Intervention schools were supported by an external organization named KPC, which specialized in training school staff and in assisting schools in setting up new curricula and guidelines. The core intervention program included: (1) antibullying training for teachers, (2) a bullying survey, (3) antibullying rules and a written antibullying school policy, (4) increased intensity of surveillance, and (5) information meetings or parents.

During the intervention, there was careful dissemination of the antibullying program to intervention schools. Also, the researchers provided information about the number of intervention and control schools, which have used the above‐mentioned elements of intervention. Finally, intervention schools were supplied with the booklet “Bullying in schools: how to deal with it” and with a “Bullying Test,” a computerized questionnaire that children could complete anonymously in the classroom.

6.17. Dutch Skills for Life

The Skills for Life program is a Dutch universal school‐based behavioral and health prevention program for adolescents aged 13–16 years old (Diekstra,  1996 ; Gravesteijn & Diekstra,  2013 ). The program targets prosocial behavior, self‐awareness, social awareness, self‐control, interpersonal skills, and ethical decision making to reduce behavioral and health problems (Fekkes et al.,  2016 ). The program is based on social learning theory and Rational Emotive Behavioral Therapy. As a result, the program aims to reduce bullying by enabling students to learn from each other in a classroom setting through behavioral modeling.

The program is implemented by teachers, who attend two 3‐day training workshops prior to implementation and receive “booster” training sessions throughout the intervention (Fekkes et al.,  2016 ). The intervention is comprised of 25 lessons that are delivered over the course of two academic years. First, four lessons address awareness and handling of thoughts and feelings. Skills such as interpersonal problem solving, emotional regulation, and critical thinking are targeted. There are twelve additional lessons in the 1st year, and nine more lessons in the 2nd year of implementation. These generally focus on skills that are applicable to particular behavioral or health experiences. For example, lessons are aimed at: dealing with bullying; setting and respecting boundaries; substance use; norms and values; friendships; sexuality; suicidal ideation; and conflicts with peers and/or teachers. Various activities are utilized throughout the program, including, active enactment, DVDs, role play, discussion and feedback.

6.18. Dynamic Approach to School Improvement (DASI)

The DASI (Kyriakides, Creemers, Papastylianou, et al.,  2014 ; Kyriakides, Creemers, Muijs, et al.,  2014 ) was a whole‐school approach to bullying prevention implemented in several European countries, such as: Cyprus, Greece, UK, Belgium and the Netherlands. This approach draws factors from the educational effectiveness model (Creemers & Kyriakides,  2008 ,  2012 ). The intervention targets specific school factors, that is, (1) school teaching policy, (2) school learning environment, and (3) school evaluation. This framework was previously found to improve academic achievement (e.g., Kyriakides,  2008 ).

At the beginning of the intervention, the research team held training for participating school staff. The theoretical framework was introduced, and a detailed manual was provided. The aim of the handbook was to facilitate school stakeholders to develop strategies and action plans that were specific to the schools' needs (Kyriakides, Creemers, Papastylianou, et al.,  2014 ). Support was offered to each school by the research team throughout the process.

Teacher surveys were distributed prior to implementation in order to highlight specific areas that needed improvement. The next phase of the intervention involved school stakeholders coming together to form cooperative committees with representatives of parents, students, and teachers. These committees then collaborated to develop action plans and strategies to address specific problems in their schools. Committees formulated plans to implement particular intervention components that best suited their specific needs. Therefore, the schools participating did not necessarily implement the same intervention components or activities. Schools were required to retain log books of activities undertaken.

Kyriakides, Creemers, and Papastylianou, et al. ( 2014 ) provide an outline of the intervention components implemented in one experimental school involved in their trial. For example, the following are identified as essential elements implemented in order to reduce bullying:

• “Student behavior outside the classroom”—involves developing clear and efficient antibullying policy, increased teacher vigilance in bullying “hot spots” and effective supervision of students.
• Improved school learning environment
• “Rewarding good behavior”—enforcing a system that acts as a nonpunitive approach to antibullying, by motivating students to behave in a prosocial manner.
• “Collaboration and interaction between teachers”—encouraging teachers to work together and communicate effectively about bullying issues in their schools.
• Other intervention components, including, encouraging and supporting peer bystanders; identifying and support “at risk” and vulnerable students; and creating student‐made videos about bullying issues.

6.19. *Ecological antibullying program

The Ecological antibullying program examined peer group and school environment processes “utilizing a systemic interactional model with evaluations at each level of intervention” (Rahey & Craig,  2002 , p. 283). The overall aim of the program was the creation of a supportive and safe school environment in which firm limits against bullying were established. The specific goals of the program included raising awareness of the problem of bullying, increasing empathy, encouraging peers to speak against bullying and formulating clear rules against bullying.

The 12‐week program was based on the “Bully Proofing Your School” program which was designed to increase the understanding of bullying and decrease the incidence of bullying (Rahey & Craig,  2002 , p. 285). The program elements included a psycho‐educational component implemented within each classroom, a peer mediation component and specialized groups for children involved in bullying.

At the school‐wide level, the psycho‐educational program was implemented by psychology students who received training sessions and manuals prior to intervention. Prior to the program, at a school assembly the program was introduced to students. The assembly signaled the formal beginning of the intervention. The classroom programs involved interactive educational approaches such as role playing and puppet techniques. The topics addressed were bullying and victimization, conflict resolution, empathy, listening skills and individual differences (Rahey & Craig,  2002 , p. 286).

Individual programs for children involved in bullying were also part of the intervention. The relevant sessions consisted of social skills, listening, empathy training and supportive counseling. Each weekly session lasted 45 min. The program also included intervention at the teacher level. Teacher programs consisted of meetings with teachers to discuss bullying, intervention approaches, and student support for those directly involved in bullying. During the intervention, the program coordinators met with principals and teachers to offer support.

6.20. Emotional Literacy Intervention

Knowler and Frederickson ( 2013 ) evaluated the effectiveness of an emotional literacy intervention targeted on bullying behaviors to reduce bullying victimization in UK schools. Selected schools were previously implementing the Social and Emotional Aspects of Learning (SEAL; Department for Education and Skills,  2005 ) program. One of the themes included in the SEAL program is “Say no to bullying” (Knowler & Frederickson,  2013 ), however the overall program aims to improve students' social relationships, motivation, learning strategies, and holistic school improvement.

The specific emotional literacy intervention implemented and evaluated by Knowler and Frederickson ( 2013 ) involved teaching emotional literacy skills to small groups of students (Faupel,  2003 ). In the current evaluation, the intervention was delivered to groups of “low emotional literacy” and “high emotional literacy” groups distinguished by scores above, or below, median scores on the Emotional Literacy assessment‐pupil form (ELA‐PF; Faupel,  2003 ). The intervention program employed 12 weekly lessons and was implemented by trained teaching aids (Knowler & Frederickson,  2013 ). The program consisted of four main concepts: (1) self‐awareness, (2) self‐regulation, (3) empathy, and (4) social skills. Lessons employed a variation of behavioral and cognitive‐behavioral elements (Faupel,  2003 ).

6.21. Empathy training program

This intervention program was developed for children identified as bullies and aimed to increase their empathetic skills in order to reduce their bullying behaviors (Şahin,  2012 ). The empathy training program was implemented over eleven 75‐min sessions that were based on a curriculum lesson plan developed by the author. Several cognitive techniques were utilized throughout the program, such as: recognizing, evaluating and naming feelings; diadtic, experimental, modeling and role‐playing, in order to improve the students' cognitive abilities in relation to empathy. Each lesson required the students to work together to develop a slogan that emulated the content of the session. The following is an outline of the first 4 weekly lessons, and the associated slogan developed, (for a full outline see: Şahin,  2012 , p. 1327; Table  2 ).

Slogan: Be kind, loving and forgiving to each other to lead a happy life .

Slogan: Living without the awareness of feelings is like driving a car with its brakes on .

Slogan: One who claims to know everything about the universe but nothing about himself, actually knows nothing .

Slogan: We can look at the same thing but view it differently .

6.22. *Expect respect

Expect Respect was a school‐based program that aimed to promote awareness and effective responses to bullying and sexual harassment. The project was developed by Safe Place, the sole provider of comprehensive sexual and domestic violence prevention and intervention services in Austin, Texas (Rosenbluth et al.,  2004 , p. 211). The program targeted the involvement of all members of the school community in recognizing and responding to bullying and sexual harassment. The overall project design was inspired by the work of Olweus (Rosenbluth et al.,  2004 , p. 212). Expect Respect consisted of five core program components, namely a classroom curriculum, staff training, policy development, parent education and support services.

The classroom curriculum was based on 12 weekly sessions adapted from a specific manual called “Bullyproof: a teachers” guide on teasing and bullying for use with fourth and fifth grade students' (Whitaker et al.,  2004 , p. 330). The Bullyproof curriculum was designed to be taught in conjunction with literature typically read by fourth and fifth graders. Although the antibullying curriculum was designed to be implemented by teachers, within the framework of the Expect Respect program, it was jointly led by Safe Place Staff and teachers or school counselors (Whitaker et al.,  2004 , p. 331). The curriculum aimed to increase the ability and willingness of bystanders to intervene in bullying situations, thus reducing the social acceptability of bullying and sexual harassment. The Bullyproof lessons included writing assignments, role‐plays of how to intervene in bullying situations, class discussions and so on.

With regard to the staff training, a 6‐h training was provided to project staff, counselors, and fifth grade teachers. The training was given by the author of the specific manual and aimed to prepare school personnel to respond effectively to bullying incidents. In addition, 3‐h training sessions were provided once per semester for all personnel, including bus drivers, cafeteria workers, hall monitors and office staff. The training presentation included research on bullying and sexual harassment; strategies to enhance mutual respect among students; practice in using lessons from the curriculum; and methods for integrating the lessons into other subject areas including language arts and health.

School administrators were encouraged to develop an antibullying policy (policy development) in their school to ensure consistent responses by all staff members to incidents of bullying and sexual harassment. Principals were expected to present the policy to school staff, students and parents. In order to facilitate the overall procedure of policy development, Expect Respect staff provided an initial policy template to school administrators (Whitaker et al.,  2004 , p. 332) and each school was encouraged to expand this initial policy in accordance with the specific needs of their unit.

The Expect Respect program also included parent training. Educational presentations were offered to parents, twice a year, providing information about the project. The information given to parents through these meetings (as well as through parent newsletters sent home) was aimed at enhancing parents' strategies to help children involved in bullying as bullies, victims, bully‐victims, or bystanders.

Further support services were provided such as continuous assistance of school counselors by Safe Place staff. School counselors were given a specialized session on how to deal with students who were repeatedly involved in bullying as either perpetrators or victims. They were also provided with a comprehensive resource manual containing reading and resource materials on bullying, sexual harassment and domestic violence.

6.23. fairplayer.manual

The fairplayer.manual is a structured, curriculum‐based antibullying program for Grade 7–9 students (Bull et al.,  2009 ; Wölfer & Scheithauer,  2014 ). The overarching aim of the intervention is to reduce bullying and relational aggression by improving students' social and moral competencies. The program focuses on raising awareness, changing attitudes, and encouraging bystander intervention.

The program is implemented over 15‐weekly 90 min lessons, and can be delivered either by trained teachers (Bull et al.,  2009 ), or psychologists (Wölfer & Scheithauer,  2014 ). Intervention lessons employ cognitive‐behavioral techniques and target nine specific topics. The first introductory lesson introduces the program to students, and class antibullying rules are developed. Two following lessons are concerned with raising awareness about bullying‐related issues, such as, the various forms of bullying and the consequences associated with perpetration and victimization. One lesson subsequently focuses on improving students' understanding of their own and peers' feelings. A further two lessons highlight the numerous participant roles involved in bullying, for example, bullies, victims, outsiders (i.e., noninvolved), assistants, and re‐inforcers (Wölfer & Scheithauer,  2014 ). The latter roles describe different forms of bystanders, those who witness bullying and allow it to happen and those who reinforce bullying behaviors. Social dynamics in the classroom is also addressed in one intervention session. By addressing the different dynamics, networks and norms socially in the class, this lesson aims to improve the classroom climate and encourage co‐operation among students. Another intervention lesson models and promotes bystander intervention in order to encourage noninvolved children to become actively engaged with intervening in bullying situations that they may witness.

Following these core awareness‐raising and knowledge‐improving lessons, participating students undertake five social skill‐training session s. These lessons focus on developing social, emotional, and moral skills of participants, in order to combat bullying. Perspective taking, empathy, and moral dilemmas are just some of the issues that are included. Diversity is the topic addressed in one of the following lessons, where students learn to respect and appreciate diversity. Finally, a concluding lesson brings together all of the issues covered by the intervention and demonstrates ways in which participants can utilize skills and knowledge in their everyday lives.

6.24. FearNot!

The FearNot! (Fun with Empathetic Agents to achieve Novel Outcomes in Teaching; Sapouna et al.,  2010 ) was an immersive learning intervention that aimed to reduce bullying victimization. Students from British and German primary schools participated in the virtual learning program for weekly 30‐min sessions over the course of three consecutive weeks. Participating schools were required to have adequate computer facilities in order to be able to run the program.

During intervention sessions bullying scenarios were enacted by male and female 3D animated characters. The content of these scenarios reflected the characters' genders, for example, scenarios involving male characters included more incidents of physical bullying, whereas female characters demonstrated more relational bullying. Following each of the bullying episodes, participants were asked to interact and provide the animated victim of bullying with a suitable coping strategy to prevent future victimization. The program then enabled students to see the outcomes of their suggested strategy. In some circumstances, the animated victim of bullying responded that they did not feel emotionally adequate enough to carry out the suggested coping strategy (e.g., not strong enough to stand up to the bully).

Based on previous research (e.g., Kochenderfer & Ladd,  2000 ), students were then provided with an indication of how successful their proposed coping mechanism would be in real‐world bullying scenarios. For example, students were provided with a score on a scale of zero (never successful) to ten (always successful; Sapouna et al.,  2010 ). In addition to the computerized program, teachers in intervention schools were provided with a detailed intervention manual. However, during the FearNot! program, teachers were instructed only to assist students with issues of comprehension, and not to guide them on suitable responses to the bullying scenarios.

6.25. Fourth R

The Fourth R: Strategies for Healthy Youth Relationships is a dating violence prevention program that targeted bullying perpetration and victimization as secondary outcomes (Cissner & Ayoub,  2014 ). This curriculum‐based intervention program was based on social learning theory (Bandura,  1978 ), and was implemented in classrooms by trained teachers during health and physical education classes. Participating teachers completed an intensive 1‐day training session that provided them with the skills to implement the program effectively. Detailed manuals and lesson outlines/materials were provided, and the Fourth R curriculum was integrated into existing health and physical education curricula.

The Fourth R was designed as a 21‐lesson curriculum that incorporates a variety of activities and lessons. Role‐playing, individual, pair and group work, and detailed examples/scenarios of conflict are examples of Fourth R‐style tasks. Program lessons were categorized into the following 3 units: (1) Personal Safety and Injury Prevention; (2) Healthy Growth and Sexuality; and (3) Substance Use and Abuse. Each unit consisted of seven 45‐min lessons. The Fourth R was also designed to be implemented in either gender‐segregated or co‐ed classrooms.

6.26. *Friendly Schools Project

“Friendly Schools” was a theoretically grounded program. Its educational techniques (e.g., role modeling, drama activities, skills training, etc.) were based on notions derived from Social Cognitive theory, the Health Belief Model and Problem Behavior theory (Cross et al.,  2004 ,  2011 ). An interesting aspect of this program is that it was based on the results of a systematic review (Cross et al.,  2004 , p. 187), which provided a set of key elements to be included in the final intervention strategy. The program targeted bullying at three levels: (a) the whole‐school community, (b) the students' families, and (c) the fourth and fifth grade students and their teachers.

With regard to the whole‐school intervention component, in each school, a Friendly Schools Committee was organized with key individuals (e.g., a parent representative, a school psychologist, a school nurse, teaching staff) who could co‐ordinate and successfully sustain the antibullying initiative. Each committee was provided with a 4‐h training, designed to build members' capacity to address bullying. Each member was provided with a specific strategy manual. The manual was a step‐by‐step guide on how to implement the antibullying initiative. It included among others the Pikas “Method of Shared Concern” and the “No Blame” approach (Cross et al.,  2011 ; Pikas,  2002 ).

With regard to the family intervention component, this included home activities linked to each classroom‐learning activity. Parents were also provided with 16 skills‐based newsletter items (eight for each year of the intervention) that aimed to provide research information on bullying as well as advice to parents on what to do if their child was a perpetrator or a victim of bullying behavior.

Moving on to the Grade 4 and 5 classroom curricula, the Friendly Schools curriculum consisted of nine learning activities per year. The curriculum was offered by trained teachers in three blocks of three 60‐min lessons, over a three‐school‐term period. The learning activities aimed to promote awareness of what was bullying behavior; to help students to become assertive and talk about bullying with teachers and parents; and to promote peer and adult discouragement of bullying behavior.

Finally, the Friendly Schools program offered manuals to teachers. The teacher manuals were designed to be entirely self‐contained so as to maximize the likelihood of teacher implementation. Friendly Schools project staff also provided teacher training (a 6‐h course) for all intervention teachers.

6.27. *Granada antibullying program

This program was a pilot antibullying program with the following aims: (a) to establish children's involvement in bullying within different participant roles/categories; (b) to reduce the number of students involved in the phenomenon as bullies, victims and bully‐victims; (c) to increase the number of students who are categorized as noninvolved in bullying, through the enhancement of prosocial skills; and (d) to identify the threats to fidelity of the program and establish the validity of the pilot program with the possibility of replicating it in future (Martin et al.,  2005 , p. 376). Forty‐nine sixth graders from one Spanish primary school in Granada participated in the program.

The program designers gathered information about the social, educational and economic background of the school, of the students' families and the community in general. That was done during 3 meetings/seminars of 3 h each. Parents, teachers and members of the educational team attended those meetings. Through these meetings, it was established that the program should target interpersonal relationships of the children. It was decided that the program would be curriculum‐based as part of the normal program of the school. It was decided that the program would be implemented by one of the researchers because the teachers did not have enough qualifications to do it and because of lack of time and resources for teacher training. Parents and teachers were provided with information about bullying (a dossier/file) that they could use to discuss the problem of bullying with children. Also, teachers could attend the intervention program so that later they would be able to implement it by themselves. Parents were invited to attend some talks on bullying that would be given by the implementation team so that the program could be continued outside the school. The program was implemented for 5 months at the classroom level (30 sessions; 3 sessions per week with one tutor, i.e., one of the evaluators).

During the first 5 sessions, the tutor informed the children about peer bullying. Topics covered in the first 5 sessions involved issues such as concept of bullying, types of bullying, how to identify it, individual and group differences in bullying, and classroom rules against bullying. From the 6th to the 21st sessions, the program emphasis was on the emotional and social abilities of the children. Several topics were covered such as: identification and expression of emotions during bullying situations; communication abilities; ability to pose questions; ability of children to give and receive complements and complaints; ability to say no in life; ability to ask for a change of behavior; and ability to solve interpersonal problems. From the 17th to the 21st sessions, the program placed emphasis on mediation.

From the 22nd to the 25th sessions, the program emphasis was on human rights. Several topics were covered such as: freedom and equality, respect of private life, respect for other people's belongings, and respect for others' opinions. Similarly, from the 26th to 30th sessions, the emphasis was on moral education. During the whole program (sessions 1–30), there was also an emphasis on the inhibition of impulsivity and enhancement of reflexivity. For the enhancement of reflexivity, the program designers used a specific program called “Programa de Intervencion para Aumentar la Attention y la Reflixividad” [PIAAR] developed by Gargallo (2000) (see Martin et al.,  2005 , p. 378). This focuses on cognitive techniques that aim to inhibit impulsivity and enhance self‐control. The program also included role‐playing, peer mediation, guided discussion, brainstorming, and drawings.

The authors acknowledge several problems with the implementation of the program such as: little involvement by parents and teachers; implementation of the program lessons during recess time or during the physical education program; lack of time to cover all the topics; no second follow‐up because of difficulties of following the children; problems with the size and selection of the sample; the instrument they used; and possible contamination of results because of the way they categorized the children (Martin et al.,  2005 , p. 382). These pitfalls could easily be spotted. For example, the evaluators indicate that they implemented the program with the most aggressive sixth graders who had the worst interpersonal problems (Martin et al.,  2005 , p. 738). This made it difficult to know whether any changes in bullying in the experimental condition were attributable to the effectiveness of the program or to regression to the mean. Also, even though they distributed a self‐report questionnaire, they categorized children based on those questionnaires only after teachers' suggestions.

6.28. *Greek antibullying program (1)

The Greek antibullying initiative was a 4‐week intervention program that aimed to minimize both bullying and victimization. The conceptual framework of the Greek antibullying program was based on the theoretical model proposed by Salmivalli in 1999 (Andreou et al.,  2007 , p. 696), according to which changing an individual's behavior (e.g., the bully's behavior) entailed motivating not only the particular person but also the rest of the group members (participant roles' approach).

The program was embedded within the wider curriculum of the fourth‐, fifth‐, and sixth‐grade classrooms and consisted of eight instructional hours, each hour corresponding to one curricular activity. The curricular activities were presented to students by their classroom teachers who received training beforehand. The teacher training consisted of five 4‐h meetings and aimed to increase awareness of the bullying problem and its seriousness as well as to raise teachers' self‐efficacy in implementing the program (Andreou et al.,  2007 , p. 697).

The Greek antibullying curriculum was divided into three parts in accordance with the three main theoretical axes proposed by Salmivalli in 1999, namely: (1) awareness‐raising; (2) self‐reflection; and (3) commitment to new behaviors (Andreou et al.,  2007 , pp. 697–698).

In line with the first axis (awareness‐raising), small‐group and whole‐class discussions were conducted (over three instructional hours) that aimed to increase students' awareness of the bullying problem. Corresponding materials included a real snap‐shot from the playground, a story entitled “A new friend” and students' own drawings. In line with the second theoretical axis (self‐reflection), two instructional hours involving classroom discussions were conducted. These discussions placed emphasis on the participant roles that students took in the bullying process. Corresponding materials involved each students' completion of open‐ended sentences. Through this activity students were intended to reflect on critical issues around the causes, benefits, feelings, and consequences of adopting different roles. In line with the final axis (commitment to new behaviors), three instructional hours of small‐group and whole‐class discussions were conducted concerning different ways of approaching or solving the peer‐conflict situation and the formulation of class rules. Corresponding materials involved an open‐ended comic‐strip for group completion to find a solution to the bullying situation presented in the relevant story.

6.29. Greek antibullying program (2)

This antibullying program was implemented in Greek elementary schools during the academic year 2011/2012 (Tsiantis et al.,  2013 ). The school‐based program incorporated many elements and was implemented by teachers. Participating teachers attended a 2‐day training seminar before implementation began. A teacher's manual (Tsiantis,  2011 ) was also provided and outlined the detailed and systematic procedures involved in the intervention. Throughout the program teachers were provided with additional support from two mental health professionals whom acted as program co‐ordinators.

The program comprised of 11 weekly workshops that were implemented for two 45‐min class periods (90‐min in total). Class activities included group discussions, games and the formation and signing of class antibullying rules (Tsiantis et al.,  2013 ). Parent meetings were also organized to increase parent participation with the intervention. The first meeting provided parents with information about the intervention program and bullying issues. During the second parent session, students presented the achievements they had made during the intervention.

6.30. Inclusive

The INCLUSIVE program is a whole‐school restorative approach to bullying prevention and intervention (Bonnell et al.,  2015 ). The program involves creating an “action group” within each participating school in order to combat bullying. These groups are comprised of a minimum of six students and six members of staff, with at least one representative from senior management, teaching, support, and pastoral staff. Each action group is appointed an external expert facilitator for the duration of the intervention. It is the facilitators' role to provide ongoing support and training to each member of the action group. Action groups were required to meet regularly throughout the intervention year, approximately once every half term.

The INCLUSIVE intervention was designed to include several core standardized intervention components, including staff training in restorative practices, and a student social and emotional skills curriculum. However, the program also allows for schools to adapt the intervention according to school‐specific needs. These needs were established using a needs assessment survey distributed to year 8 students prior to commencement of the intervention. This survey aimed to establish student views on bullying and aggression in their schools, while providing information regarding school engagement and connectedness, perceptions of safety/risks, social support and social skills, relationships, and teaching in personal, social and health (PSHE) classes. Results of the needs assessment survey were then employed by the action group to tailor the INCLUSIVE intervention to target specific needs. The action groups also utilized this information to review and improve schools' existing policies, procedures and schemes (e.g., peer mediation and “buddying” schemes).

In relation to the core components of the INCLUSIVE intervention, all school staff were provided with introductory training in restorative practices by their affiliated expert facilitator. A minimum of twenty school staff were also required to attend intensive training provided by a specialist training provider. Restorative practices, such as “Circle Time,” were taught to staff to improve school climate and student‐staff communication. This technique involves teachers and staff sitting together in a circle discussing various emotional, social, and curricular issues. Each member of the circle is considered a valued contributor, and all inputs are treated equally. Circle time aims to support student communication and promote positive relationships. Another restorative technique used in the INCLUSIVE program was “formal conferencing,” which aimed to deal with serious bullying and aggressive incidents directly. Formal conferencing involves bringing together teachers, parents and students to establish appropriate punishment and ways in which the harm caused can be repaired. This approach emphasizes a nonjudgmental and inclusive environment so that both victims and perpetrators of bullying and/or aggression are involved.

Year 8 students also completed 5–10 h of social and emotional skills training throughout the process of the INCLUSIVE intervention. These lessons were based on the Gatehouse Project curriculum and could be delivered as either stand‐alone modules or integrated into existing academic curriculums. Modules covered included: (1) Establishing respectful relationships; (2) Emotion management; (3) Understanding and creating trusting relationships; (4) Exploring others' needs and avoiding conflict; and (5) Maintaining and repairing relationships.

6.31. *KiVa

The name of this project is an acronym of the expression “Kiusaamista Vastaan” which means “against bullying.” The word “kiva” in Finnish means “nice” and this is why this acronym was chosen for the specific antibullying initiative in Finland. Regarding the overall perspective of the program, the KiVa project included a universal and an indicated intervention (Kärnä et al.,  2011a ,  2011b ,  2013 ; Nocentini & Menesini, 2016; Salmivalli et al., 2007). The universal intervention referred to efforts made to influence the group norms while the indicated intervention referred to the way in which specific cases were handled in schools through individual and group discussions between the teacher and the students involved (Salmivalli et al., 2007, p. 6).

The KiVa program included a large variety of concrete materials for students, teachers, and parents. It also utilized the Internet and virtual learning environments (e.g., computer games against bullying) aiming in this way to enhance students' attitudes against bullying. Also, students received their own personal user ID, which they could use as a password before the completion of each web‐based questionnaire on bullying. KiVa included 20‐h student lessons, which were carried out by student teachers. The lessons involved discussions, group work, short films about bullying, and role‐playing exercises. After each lesson, a class rule was adopted, based on the central theme of the lesson.

A unique feature of the KiVa program was the use of an antibullying computer game. The game involved five levels and the teacher always activated the next level of the game after the relevant lesson was completed. Students were able to begin using the game after the third lesson; the second level of the program was played after the fifth lesson, and so on until the end of the school year. Each level of the computer game included three components that were named as “I know,” “I can,” and “I do.” In the first component, students were informed about basic facts on bullying. In the second component, the “I can”‐component, students moved around in the virtual school and faced different challenging bullying incidents. Finally, the third component was used to encourage students to make use of their knowledge and skills in real life situations.

Another important element of the KiVa project was the teacher training. Teachers were also provided with vests that they could use during playtime while supervising the school yard. This simple technique aimed to enhance teachers' visibility in the schoolyard and to signal that bullying was taken seriously in the school. Also, all teachers carrying out the KiVa program could seek advice from a web‐based discussion forum, where they could share experiences and ideas about bullying with other colleagues.

Within the school framework, the program also facilitated the use of a peer support group for victims of bullying. The classroom teacher was expected to arrange a group with 2–4 classmates—those who were pro‐social and had high status in the class—who were expected to provide support to victimized students, thus sustaining healthy peer relationships. An interesting element in the KiVa program is that it incorporated both punitive and nonblame approaches when dealing with perpetrators of bullying. Half of the school teams were instructed to use more punitive approaches (e.g., what you have done is wrong and it has to stop right now) while the rest of the school teams were instructed to use no‐blame approaches in their discussions with children (e.g., “your classmate is also having a hard time and this is why he behaves like that; what could we do to help him?”). There was also co‐operative group work among experts when dealing with children involved in bullying.

Finally, the KiVa program involved parents. A parents' guide was sent to the home and provided information about bullying and advice on how parents could be involved to reduce this problem. Information nights for parents were also organized and provided.

6.32. Lead Peace Intervention

The Lead Peace intervention is based on a resiliency conceptual framework (Resnik,  2000 ), thus, aims to reduce youth problem behaviors using an assets‐based approach (Harpin,  2011 ; Sieving & Widome,  2008 ). The intervention was developed as a school‐based “service learning and health education” program to reduce risk of violence and school failure in middle school students (Sieving, 2006). Developed from the Points of Light Youth Leadership curriculum for 9th to 12th grade students (Sieving, 2006), the program was adapted for use with Grade 6–8 students (Harpin,  2011 ).

The core curriculum targets factors on three levels: (1) environmental (e.g., adult resources and supports, family norms and behaviors, peer norms and behaviors, school/community opportunities and social connectedness); (2) personal (e.g., attitudes, beliefs, perceived norms, emotional distress); and (3) behavioral (e.g., social and emotional skills, coping behaviors, school performance). The program aims to reduce risky health and social behaviors (e.g., interpersonal aggression, physical fighting, bullying) in order to promote positive and reduce risky behaviors. The curriculum is implemented for 3 years, and can be delivered in two “doses”: (1) Lead Peace program (basic)—includes 15–20 intervention lessons each year; or (2) Lead Peace plus program—includes 30 intervention lessons, 15–20 additional community service hours, and health education and family outreach activities.

6.33. Lunch Buddy Mentoring program

The Lunch Buddy mentoring program was a school‐based antibullying program that aimed to reduce bullying victimization in elementary school children (Elledge et al.,  2010 ). The program was based on previous research that suggests youth mentoring can be utilized as an effective prevention technique (Dortch, 2000). In comparison to peer‐mentoring antibullying program, the Lunch Buddy program employed college student mentors based on prior success of college student mentoring aggressive children (Cavell & Hughes,  2000 ).

Mentors were provided with training prior to implementation of the program and participated in weekly meetings throughout the program. Children were identified as potential participants using a self‐ and teacher‐report victimization index. The self‐report School Experiences Questionnaire (Kochenderfer & Ladd,  2000 ) and teacher ratings of child victimization due to physical, verbal and relational aggressive were combined to create this index. School principals also collaborated with counselors to identify potentially suitable candidates. Eligible participants were then matched with same‐sex college student mentors, based on the availability of mentors during the mentees scheduled lunchtimes. Mentors visited the mentees twice a week, over the course of 5–6 months. During these visits mentors were required to sit with their mentee and their peers during lunchtime. Each mentor was also required to complete a log sheet after each visit.

6.34. Media Heroes

Chaux et al. ( 2016 ) evaluated the effectiveness of the cyberbullying prevention program “Media Heroes” [ Medienhelden ] on reports of traditional school bullying. The Media Heroes program is based theoretically on the Theory of Planned Behavior (Ajzen,  1991 ) and the social context of participant roles in bullying (Salmivalli,  2010 ). The program aims to reduce cyberbullying perpetration by enhancing empathy, increasing awareness and knowledge about what constitutes cyberbullying, the safety risks associated with Internet activity, and by providing assertive and useful methods in which bystanders can intervene in cyberbullying (Chaux et al.,  2016 ).

There are two versions of Media Heroes: (1) a short version implemented over four 90‐min lessons that take place in one school day; and (2) a long version that is implemented over 15‐weekly 45‐min lessons (Schultze‐Krumbholz et al.,  2012 ). Intervention activities include, role‐playing, class debates, news and film content, group learning and student‐parent presentations (Chaux et al.,  2016 ). Measures of both traditional‐ and cyber‐bullying were implemented in this evaluation, due to the significant overlap in the prevalence of these behaviors.

6.35. NoTrap!

Noncadiamointrappola (Let's Not Fall into a Trap), or NoTrap!, is a web‐based antibullying program that has been developed, implemented and refined over several studies (Menesini et al.,  2012 ; Palladino et al.,  2012 ,  2016 ). Initially implemented in two Italian schools in 2008, the program involves students actively engaging in the development of a website promoting antibullying (Menesini et al.,  2012 ). A selected number of students per school are provided with training and enroll as online peer‐educators. These students acted as online moderators of an antibullying forum, regulating discussion threads and responding to users' questions and concerns (Menesini et al.,  2012 ). In addition, peer‐educators also conducted face‐to‐face awareness raising workshops and meetings with their classmates, to highlight the key issues surrounding traditional‐ and cyber‐bullying (Palladino et al.,  2016 ).

Subsequent editions of the NoTrap! program incorporated additional elements based on findings from previous evaluations. For example, Palladino et al. ( 2012 ) placed more emphasis on: (1) victims' roles and victim support, (2) involving bystanders, (3) greater involvement of teachers in antibullying activities, and (3) creation of a Facebook group to supplement online materials. The third revision of the NoTrap! program incorporated standardization of the face‐to‐face antibullying activities led by peer educators (Palladino et al.,  2016 ). New peer‐led activities involved group work that targeted empathy and problem‐solving skills (Palladino et al.,  2016 ).

6.36. *Olweus Bullying Prevention Program

The OBPP was a multilevel program aiming at targeting the individual, the school, the classroom and the community level. Apart from marked mass‐media publicity, the program started with a 1‐day school conference during which the problem of bullying was addressed between school staff, students, and parents. This signaled the formal commencement of the intervention. Two different types of materials were produced: a handbook or manual for teachers (entitled “Olweus” core program against bullying and antisocial behavior') and a folder with information for parents and families. The program also included: (1) CD‐program that was used for assessing and analyzing the data obtained at the pre‐test period, so that school‐specific interventions could then be implemented; (2) a video on bullying; (3) the Revised Olweus Bully/Victim Questionnaire and (4) the book “Bullying at school: what we know and what we can do.”

The antibullying measures mainly targeted three different levels of intervention: the school, the classroom and the individual. At the school level, the intervention included:

• Meetings among teachers to discuss ways of improving peer‐relations; staff discussion groups.
• Parent/teacher meetings to discuss the issue of bullying.
• Increased supervision during recess and lunchtime.
• Improvement of playground facilities so that children have better places to play during recess time.
• Questionnaire surveys.
• The formation of a coordinating group.

At the classroom level the intervention included:

• Students were given information about the issue of bullying and were actively involved in devising class rules against bullying.
• Classroom activities for students included role‐playing situations that could help students learn how to deal better with bullying.
• Class rules against bullying.
• Class meetings with students.
• Meetings with the parents of the class.

At the individual level the intervention included:

• Talks with bullies and their parents and enforcement of nonhostile, nonphysical sanctions.
• Talks with victims, providing support and providing assertiveness skills training to help them learn how to successfully deal with bullying; also, talks with the parents of victims.
• Talks with children not involved to make them become effective helpers.

An interesting feature of the OBPP is that it offered guided information about what schools should do at both the intervention and the maintenance period. The Olweus program demands significant commitment from the school during the 'introductory period' which covers a period of about 18 months. Later the methodology acquired by the staff and the routines decided by the school may be maintained using less resources … Yet, even for the maintenance period, the program offers a point by point description of what the school should do to continue its work against bullying in accordance with Olweus methodology (Olweus, 2004c, p. 1). Also, at the school level training was offered to the whole school staff, with additional training provided to the coordinators and key personnel. These were responsible for coordinating the overall antibullying initiative in their school. The program also included cooperation among experts and teachers (e.g., psychologists) who worked with children involved in bullying.

6.37. Positive Action program

The Positive Action Program is a generalized school‐based “well‐being” program (Lewis et al.,  2013 ). The program targets both distal (e.g., school climate and teacher classroom management) and proximal (e.g., students' thoughts, feelings, and self‐efficacy) facets are targeted in order to impact a range of health‐ and behavioral‐related outcomes (Li et al.,  2011 ). The program is based on three core elements.

First, the Positive Action philosophy. Based on the theory of self‐concept (Combs,  1962 ; Purkey,  1970 ; Purkey & Novak,  1996 ) and a Positive Psychology (Frederickson, 2000; Seligman & Csikszentmihalyi,  2000 ) approach, the philosophy emphasizes positive feelings about the self, to encourage positive behaviors toward others (Flay & Allerd,  2010 ). Second, the Thoughts‐Actions‐Feelings Circle concept is used throughout the program to illustrate the reinforcing cycle of thoughts, feelings and actions. This is delivered to outline that positive thoughts lead to positive actions, positive actions in turn lead to positive feelings, which then reinforce positive thoughts. Third, a strict six‐unit curriculum that involves daily lessons, interactive learning and social‐emotional skill development.

The PA curriculum is designed to be adapted for kindergarten to Grade 12 students, and is based on six key concepts: (1) self‐concept; (2) social and emotional positive actions for managing oneself responsibly; (3) positive actions relating to a healthy body and mind; (4) honesty with oneself; (5) getting along with others; and (6) continuous self‐improvement (Lewis et al.,  2013 ). The intervention program also involves teacher, parent/family and community training. Schools implementing the PA program receive support from developers throughout implementation by training, manuals, school‐wide climate development, counselors, family classes, and individual consultations for staff with a PA implementation coordinator.

6.38. Preventure and Adventure CBT

The Preventure and Adventure intervention programs were part of two 2 year longitudinal projects that targeted adolescent alcohol use and bullying behaviors (Topper,  2011 ). Intervention components were primarily personality‐targeted cognitive behavioral therapy (CBT) for “high risk” students. Participants were screened prior to taking part in the intervention for four individual personality domains: (1) hopelessness; (2) anxiety‐sensitivity; (3) sensation seeking; and (4) impulsivity. Students who were classified as being “high risk” on any of the four domains were invited to participate, and assigned to one of four potential intervention workshops. These intervention sessions were CBT‐based and were aimed at each of the four personality domains. Thus, a student who scored highly on the impulsivity measure was assigned to the impulsivity‐focused CBT session. For participants that scored above the mean on multiple measures, they were assigned to the session that corresponded to the personality domain that they deviated the most from standardized scores.

High risk students in each school were randomly assigned to either the intervention or control condition, as were “low risk” students, for comparison. The Preventure study took place between 2005 and 2007, and either a chartered counseling psychology, an experienced special needs teacher, or a master‐level research assistant implemented intervention workshops. In comparison, the Adventure study took place between 2007 and 2009, and although the intervention sessions followed the same procedure, they were implemented by trained teachers in each school.

6.39. *Pro‐ACT+E program

Pro‐ACT+E was a universal, multidimensional program that aimed to prevent bullying in secondary schools (Sprober et al., 2006). It involved a cognitive‐behavioral approach to the problem of bullying and victimization by building up prosocial behavior. The program was universal: it did not involve specific work with perpetrators or victims of bullying. However, it included both teacher and parent training and a 2‐h classroom discussion with students about violence problems. The program offered curriculum materials that aimed to increase awareness in relation to the problem of bullying and placed emphasis on specific issues such as classroom management and classroom rules against bullying.

6.40. *Progetto Pontassieve

The program was delivered in a period of 3 years, and it consisted of two main parts. During the 1st two years it was delivered more at the school level whereas the 3rd year was more at the class and individual level (Ciucci & Smorti,  1998 ). During the 1st year a training course for teachers took place addressing psychosocial risks for children and bully‐victim problems. At the end of the training, a study was conducted to reveal how serious was the problem of bullying and what were its characteristics. The 2nd year of the intervention included a counseling service for each individual who was affected by bullying.

The intervention took place in the 3rd year and was based on the use of two different methods: Quality Circles, where pupils had to cooperate to find practical solutions to their problems, with the use of the Interpersonal Process Recall which consisted of the recording of one Quality Circle and discussion about it. The other method used was Role Playing conducted in small groups with subsequent class discussions, which helped students to examine possible strategies to face and overtake bullying problems. The aims of both of these methods were to make students aware that they could intervene in an efficient way to reduce bullying.

6.41. *Project Ploughshares for Peace

Project Ploughshares Puppets for Peace (P4 program) was an antibullying program that aimed to educate elementary school students about bullying and conflict resolution (Beran & Shapiro,  2005 , p. 703). The P4 program used puppets and a 30‐min script. Using three‐feet, hand‐and‐rod puppets, two puppeteers enacted a story that involved direct and indirect bullying, as well as a successful resolution to this scenario. These behaviors occurred among two female puppets and a male puppet friend.

After watching the play, students were invited to identify the bullying behaviors. During the discussion, four main strategies—presented as “4 Footsteps”—to deal with bullying were suggested to pupils: (1) ignore, (2) say stop, (3) walk away, and (4) get help. The show took approximately 45 min and aimed to increase children's awareness about which behaviors could be categorized as bullying and to show various strategies that children who were bullied and/or who witnessed bullying could use to discourage it (Beran & Shapiro,  2005 , p. 703).

6.42. Rational Emotive Behavioral Education (REBE) and ViSC

Trip et al. ( 2015 ) implemented a dual program consisting of REBE (Trip & Bora,  2010 ) and ViSC social competence (Strohmeier et al.,  2012 ) elements. These components were combined to address both social and emotional factors involved in bullying and positive youth development (PYD). This program approaches bullying from a sociological perspective, including factors on the individual, family, peer, classroom, and school levels (Espelage & Horne,  2008 ; Swearer & Espelage,  2011 ).

ViSC social competence program is a systemic approach to antibullying that targets students, teachers and parents (Strohmeier et al.,  2012 ). Implemented by teachers in the classroom, the program comprises several intervention units that aim to: (1) foster empathy and perspective training, (2) enhance responsibility, and (3) improve students' behavioral responses to bullying (Trip et al.,  2015 , p. 733).

REBE elements employed by Trip et al. ( 2015 ) on the other hand, target specific elements of aggression that are lacking in the ViSC units. Based on the theory of Rational Emotive Behavioral Therapy (Ellis,  1962 ), the REBE elements of the intervention program target the difference between desire and reality (Trip & Bora,  2010 ) and anger. The REBE program activities target specific elements of anger, specifically, anger triggers, personal experiences of anger and the consequences of anger (Trip et al.,  2015 ).

6.43. Restorative Whole‐school Approach (RWsA)

The RWsA (Hopkins,  2004 ; Morrison,  2002 ) was a school‐based antibullying initiative that employs a restorative justice inspired philosophy. Hence, the program focuses on creating a positive school environment to prevent bullying in the long‐term, rather than a short‐term disciplinary and punishment approach (Wong et al.,  2011 ). The program had three core goals: (1) to create a positive and harmonious school learning environment; (2) implement an interactive classroom curriculum; and (3) encourage an effective partnership between teachers, students, parents and relevant professionals.

A whole‐school antibullying nonpunitive ethos and policy is implemented as the core of the intervention (Wong et al.,  2011 ). This policy aims to establish a positive school environment in order to combat bullying‐related risk factors. The curriculum lessons incorporated elements on various issues, including, empathy, assertiveness, coping, problem‐solving, and conflict resolution.

6.44. Resourceful Adolescent Program (RAP)

The RAP is a classroom‐based CBT intervention designed for adolescents aged 12–15 years of age (Stallard et al.,  2013 ). The program is a depression prevention program, however, bullying problems were included as secondary outcomes. The program incorporates a detailed manual and student workbooks, and was implemented over nine sessions, of approximately 50–60 min each. The core components include: psycho‐education, helpful thinking, identifying personal strengths, keeping calm, problem solving, support networks, and keeping the peace. The program was designed to flexible and adaptable to participating schools' varying busy timetables.

6.45. *S.S. Grin

The Social Skills Group Intervention (S.S. GRIN) was a school‐based program that aimed to help children enhance their social skills. S.S. GRIN was designed as a social‐skills training intervention for peer‐rejected, victimized, and socially anxious children. It could be applied to an array of problems that are social in nature (e.g., aggression, low self‐esteem, depression, social anxiety, social withdrawal) not just bullying (DeRosier & Marcus,  2005 , p. 140). The authors argued that the program went beyond the most common social‐skills training (De Rosier & Marcus, 2005, p. 141) by emphasizing the cognitive aspects of relations and emotions. That is, children were not only taught prosocial skills, but they were also taught, on the cognitive level, how to identify negative perceptions and behaviors in an effort to help children to regulate their own emotions as well as enhance their coping skills.

Overall, the program was a combination of social‐learning and cognitive‐behavioral techniques, used to help children build social skills and positive relationships with peers. It was a highly structured, manualized program (DeRosier,  2004 , p. 197) with a number of sessions containing scripts and activities to undertake. Each session included didactic instruction combined with active practice such as role‐playing, modeling and hands‐on activities (De Rosier, 2004, p. 197). The children participated in group sessions for eight consecutive weeks. Each session lasted approximately an hour. The groups were led by each school's counselor and an intern, who were trained and supervised by one of the program instructors (De Rosier & Marcus, 2005, p. 143).

6.46. School‐based Drama program

This school‐based antibullying program was based on drama (Owens & Barber,  1998 ) and social cognitive theories (Bandura,  1978 ). The main aim of this project was to design and implement a drama‐based program to improve social relationships and social/emotional well‐being in children, which in turn may help to reduce bullying (Joronen et al.,  2011 ). Targeted concepts included: empathy; social competence; student‐teacher interaction; child–parent interaction; and recognition of values/emotions.

This program was developed by the combined efforts of researchers, drama experts and teachers. It was implemented in‐class by trained teachers and school nurses over a period of 6 months. Teachers and school nurses attended a 2‐day seminar and received two drama handbooks, however, there was no manual or fixed program outline provided. Support was provided through email communication between teachers and researchers for the duration of program implementation. Teachers conducted one drama session per month with their class. These sessions covered a variety of topics, including, bullying, friendship, loss of a friend, supporting a bullied peer, tolerance, and child abuse.

6.47. School‐wide Positive Behavioral Interventions and Supports (SWPBIS)

SWPBIS was a universal behavioral intervention program that targets school‐level factors in order to improve school climate and promote positive student and staff behaviors (Waasdorp et al.,  2012 ). Instead of following a specific antibullying curriculum, SWPBIS aimed to reduce bullying by targeting schools' discipline and behavioral management strategies. A SWPBIS team in each school organized and facilitated the intervention implementation.

These teams were responsible for developing a set of “positive expectations” for the school. These were a number of statements that outlined what the school expected in relation to student and staff behavior, for example, “be responsible, respectful, and ready to learn” (Waasdorp et al.,  2012 , p. 150). Posters highlighting the expectation statements were then displayed all around participating schools, both in classrooms and outside of classrooms, and are positively reinforced using reward systems. Furthermore, data from student surveys and discipline referrals were employed throughout the intervention to inform teachers of potential bullying “hot spots” that require increased supervision and monitoring. School staff also received training on classroom management and how to respond consistently and effectively to bullying. Additionally, students identified as being “high risk” or vulnerable to bullying behaviors or victimization were provided with selective intensive intervention.

6.48. School bus antibullying intervention

This intervention program was a universal antibullying program designed to reduce the prevalence of bullying behaviors on school buses (Krueger,  2010 ). The program was purposefully developed and utilizes materials and content from the “Take a Stand, Lend a Hand, Stop Bullying Now!” tools that are available free of charge.

The intervention was implemented with elementary school children over five consecutive days, during the final 20‐min of the school day. Lessons were delivered by the school's social worker and principal to two groups (kindergarten to 2nd grade students, and 3rd to 5th grade students) of participants. The program followed this format from days 2–5, however, on day 1, all participants completed the introductory lesson together. The school‐bus antibullying program primarily utilized DVD materials from the “Take a Stand” content. These video clips depicted cartoon characters engaging in different bullying scenarios.

On day 1 (i.e., the introductory lesson) an overview of school bullying and related issues, including bystander intervention, was provided to participants. The associated DVD clip depicted a male character physically bullying another child in the playground while other students watched. Participants then discussed the clip in groups, and were introduced to the “Three Steps to Stop Bullying Chart.” This technique involves three steps, Stop, Help , and Tell , that bystanders can take if they witness bullying.

On each subsequent day, a new DVD clip was shown to participants and the Stop, Help , and Tell concepts were revisited. The school's social worker or principal led discussion groups by posing questions to the students concerning the feelings and emotions experienced by the victim of bullying, potential coping strategies that the victim could use, and possible bystander behaviors. Participants also shared their previous experiences with similar situations. Furthermore, using the Stop, Help , and Tell paradigm, participants brainstormed potential ways to tell a bully to stop behaving in a certain manner, ways to help the victim and appropriate trusted adults that they can tell about the situation.

6.49. Second Step

The Second Step: Student Success Through Prevention is a middle school Social‐Emotional Learning (SEL) program that aims to reduce bullying, peer victimization, physical aggression, homophobic name‐calling and sexual violence (Espelage et al.,  2013 ,  2015 ). The intervention curriculum is taught in‐class by trained teachers. Lessons are interactive and engaging, requiring students to take part in whole‐class, small group and individual work. A take home task is also given after each lesson to reinforce skills learned. DVDs are also used to accompany and enrich lesson content.

The 6th grade Second Step curriculum involves 15 weekly lessons on various social and emotional skills and bullying‐related topics. The following outlines the curriculum: (1) empathy and communication—five lessons; (2) bullying—two lessons; (3) emotion regulation (e.g., coping with stress)—three lessons; (4) problem‐solving—two lessons; and (5) substance abuse prevention—four lessons.

Each lesson has clearly outlined learning objectives to reduce problem behaviors and increase prosocial behaviors. For example, lessons on bullying target the peer context by increasing knowledge, improving attitudes, and encouraging bystander intervention in order to reduce bullying perpetration and victimization. Students are educated about the differences between types of bullying, importance and responsibilities of bystanders in preventing bullying and a number of positive bystander behaviors are modeled. The 7th grade Second Step curriculum involves a similar lesson structure, with some slight changes. The intervention is delivered over 13 weekly lessons, and cyber‐bullying and sexual harassment issues are incorporated into bullying modules.

6.50. Shared Concern

Wurf ( 2012 ) assessed the effectiveness of the whole‐school approach to bullying intervention and prevention, with a particular emphasis on Pikas' ( 2002 ) nonpunitive method of shared concern. The Pikas method of Shared Concern is a teacher, or counselor, implemented intervention, that is divided into five key stages. First, the intervener identifies the students involved in bullying and talks with them individually. These discussions aim to provide nonpunitive and constructive options for both bullies and victims (Wurf,  2012 ). The second and third stages involve providing empathy and ongoing support to the victims of bullying. Finally, the fourth stage incorporates a mediation session between bullies and victim(s). A conflict resolution approach to prevent bullying is agreed upon and implemented by all involved. The fifth and final stage occurs during the follow‐up period, whereby the teacher or counselor monitors the involved students to ensure that the bullying has stopped.

6.51. *Short Intensive Intervention in Czechoslovakia

The antibullying intervention in Czechoslovakia was inspired by the OBPP and borrowed elements from it, such as the Olweus videocassette on bullying (Rican et al.,  1996 , p. 399). The Olweus bullying questionnaire was used to measure several aspects of bullying within the schools. A peer nomination technique was also used to identify bully and victim scores. The relevant results from both measurement scales were presented to teachers in the intervention schools to increase awareness of the problem of bullying. The program researchers discussed with the teachers “possibilities of an individual approach to the bullies as well as to the victims” (Rican et al.,  1996 , p. 399).

As another intervention element, teachers were instructed to introduce relevant ethical aspects into the curriculum where possible: the ideal of knighthood was suggested for history classes and the ideal of consideration for the weak was introduced in sentences used for dictation and analysis (Rican et al.,  1996 , p. 400). Another element of the intervention involved the use of a method called “class charter.” Specifically, children were asked to indicate how they would like their teachers and other classmates to behave toward them as well as how students should behave toward teachers and among themselves. The final aim of this classroom activity was the construction of a set of rules and principles, which was then signed by all pupils in the classroom and placed there in a visible position. Finally, the Olweus video‐cassette on bullying was shown to children and was used as a means of promoting the antibullying idea in the school.

6.52. *Short Video Intervention

This antibullying strategy, involved a single viewing of an antibullying video, entitled Sticks and Stones, and aimed to examine its effects on secondary school students' views of, and involvement in, bullying. The program aimed to examine both attitudes toward bullying and the actual behavior since “it would not be unreasonable to propose that these attitudes will influence actual behavior” (Boulton & Flemington,  1996 , p. 334). The program involved only one school that had no prior antibullying policy.

The video presented pupils (either in groups or on their own) talking about bullying, their views about this phenomenon and their personal experiences of bullying. The video also involved a number of bullying scenes (see Boulton & Flemington,  1996 , p. 337 for examples).

6.53. Social and Emotional Training (SET) intervention

This intervention program was a school‐based SET mental health program for Swedish school children (Kimber et al.,  2008 ). The SET program was primarily focused on mental health, but also targeted other aspects of participants' lives, such as bullying. Both internalizing and externalizing aspects of child mental health are addressed.

Trained teachers delivered the program over the course of two academic years. Intensity of program implementation varied according to the age of students. Junior students (i.e., grades 1–5) received the program in 45‐min sessions twice a week, while senior students (i.e., grades 6–9) completed one 45‐min session per week. Program developers provided each participating teacher with detail manuals for implementing the program with each grade and grade‐specific student workbooks. Role‐playing and modeling tasks covered many themes, including: social problem solving; conflict management; dealing with strong emotions; and resisting peer pressure. Teachers were also supervised once a month during the 1st year of implementation, and students were encouraged to practice skills both at school and at home.

6.54. Social Norms Project

Lishak ( 2011 ) implemented an antibullying program based on social norms theory (Perkins,  2003 ) with middle school students. The program was implemented over a period of 12 weeks and was developed based on student responses to an anonymous web‐based survey and student discipline and suspension reports (Lishak,  2011 ). Student surveys collected information regarding perceptions of bullying in the school and results were then relayed to participants via weekly lessons, assemblies, posters, and media content throughout the school. Data from school discipline, suspension and visitation logs were collated to estimate the prevalence of bullying and school violence.

6.55. *Social Skills Training (STT) program

STT was a program specifically designed to support “chronic victims” of bullying (Fox & Boulton,  2003 , p. 237). The general aim of the program was to help children improve their social skills, therefore reducing a child's individual risk of victimization (Fox & Boulton, 2003 , p. 234). The program involved an 8‐week course during which children learnt how to use both problem‐solving and relaxation skills, how to think positively, how to modify their nonverbal behavior and how to use some verbal strategies such as “fogging” and “mirroring” (Fox & Boulton,  2003 , p. 235).

During the program, victims of bullying were gathered in groups of five to ten and were exposed to the aims of the program for 1 h/week. Two trainers delivered the 1‐h sessions throughout the program. The 1st week was dedicated to children introducing each other and listening each other's problem. The next two sessions dealt with issues of friendship and aimed to help children form strong friendships (e.g., having conversations; asking to join in), while the fourth session dealt with issues of body language: teaching children how to modify their nonverbal behavior in a way that would protect them from being victimized. During the fifth session children learned how to be assertive while in the next two sessions children were taught how to deal with the bully. The eighth session signaled the end of the program.

6.56. *SPC and CAPSLE program

This evaluation compared the effects of two intervention packages with a treatment‐as‐usual condition (Fonagy et al.,  2009 ). Nine schools were randomly allocated to the two experimental and one control (treatment‐as‐usual) conditions after a stratified allocation procedure, which was used to stratify schools based on the percentage of low‐income students (indicated by students' free‐ and reduced‐lunch status). In the experimental conditions, the full intervention was offered for 2 years (the efficacy phase) with a limited 3rd year of intervention (the maintenance phase).

The first experimental condition involved a “School Psychiatric Consultation” (SPC), a manualized protocol that aims to address mental health issues of children with disruptive behavioral problems, internalizing problems, or poor academic performance. SPC was a school‐level intervention focused on individual children. Three child psychiatry residents, supervised biweekly by a senior child psychiatrist, delivered mental health consultation following the SPC manual for 4 h/week. The psychiatric residents attended weekly school resource meetings and consulted directly with teachers, parents and other school personnel, through classroom observations and meetings, providing 140 consultations for 65 students in year 1 and 97 consultations for 45 students in year 2.

The second experimental condition involved the implementation of CAPSLE (“Creating a Peaceful School Learning Environment”), a manualized psychodynamic approach addressing the cocreated relationship between bullies, victims and bystanders. In contrast to SPC, CAPSLE represents a whole‐school intervention approach. It aimed to modify the educational and disciplinary school climate. A CAPSLE team drawn from school staff in the pilot project led implementation in the two intervention years using a training manual. In year 1, teachers received a day of group training, students received nine sessions of self‐defense training, and the CAPSLE team consulted with school staff monthly. Year 2 started with a school‐wide half‐day refresher self‐defense course, and consultation continued with counselors, teachers and adult/peer mentor programs. In year 3 (the maintenance phase), self‐defense training continued as in year 2.

CAPSLE includes several antibullying materials that can be used by teachers such as a Teacher Discipline Manual (used in the teacher training), a Student Workbook, Buttons and Magnets and Patches (used as a way of reinforcing of desirable student behavior), Parent Warning Notes (notifying parents about specific problem behavior of the child) as well as antibullying videos that can be used during the physical education lessons (and videos that can be used by parents). CAPSLE also includes the Gentle Warrior Program, a 12‐week curriculum specifically designed for physical education teachers. For CAPSLE, intervention fidelity was assessed using a teacher self‐report measure that required teachers to state the frequency with which various CAPSLE program components were implemented.

6.57. Standard CBT and CBT plus media program

This intervention program combined elements of standardized CBT and DVD bullying‐related materials in order to reduce bullying perpetration and victimization among elementary school children (McLaughlin,  2009 ). The standardized CBT lessons were delivered by a trained counselor, and focused on bullying and aggression relation issues. Two experimental groups were employed, one of which received only the CBT lessons, and the other completed the CBT lessons and were shown the bullying DVDs.

The program was implemented over 4 weekly lessons that followed a strict outline. In week 1, the lesson focused on defining bullying, identifying bullying roles and different forms of bullying, and exploring the possible characteristics of bullies, victims, and bystanders. Week 2's lesson was concerned with establishing the consequences of bullying for all those involved, including the bully, victim and bystanders. Empathy for victims of bullying was also developed. Activities included creating feeling lists, and participating in role plays. Lesson three aimed to promote bystander intervention by developing awareness and knowledge of appropriate responses to bullying, suitable ways to intervene, and promoting assertiveness. Classes are taught using educational and informative posters. The final lesson, in week 4, aimed to outline the gender differences in bullying, why these occur, and ways to combat gender‐specific forms of bullying. In their classes, students establish class antibullying rules and are taught about the support available in school to stop bullying.

In addition, students in the CBT + media experimental group watched three DVDs that highlighted the issues outlined in the weekly lessons. The DVDs that were shown are as follow: (1) Let's Get Real , which shows young people talking about their personal experiences of bullying; (2) The Deepest Hurt , that depicts girls role‐playing various scenarios of relational aggression; and (3) The Broken Toy , a dramatization of the damage bullying can cause. Following the videos, students engaged in group discussions led by the counselor about the issues illustrated in each DVD.

6.58. *Stare bene a scuola: Progetto di prevensione del bullismo

This intervention was based on the curriculum activities and the whole school approach because it tried to involve all people in a school (Gini et al.,  2003 ). The program was delivered to 6 schools and included several activities. Teachers were first trained in 3 days on “cooperative learning” and in particular on the Jigsaw technique. Teachers then had an on‐going supervision once every 15 days. The intervention in the class lasted 4 months with two meetings a week. The intervention was directed toward the following areas: (1) awareness of the body and what it feels; (2) emotional awareness; and (3) bullying awareness. These areas were dealt with in each of the sessions, starting from the first one. For each thematic area, several activities were conducted and several methods were used.

6.59. Start Strong

“Start Strong: Building Healthy Teen Relationships” was a school‐based curriculum focused teen dating‐violence prevention program (Williams et al.,  2015 ). The program was implemented over 2 years in four experimental schools (that implemented the program) and four comparison schools (that did not implement the program). Schools were matched based on: school size, percentage of students eligible for free school lunches, race/ethnicity, and socioeconomic status. The effectiveness of the program was measured for outcomes that included the perpetration and victimization of teen dating‐violence, bullying and sexual harassment.

6.60. *Steps to Respect

The Step to Respect program aimed to tackle bullying by: (1) increasing staff awareness; (2) fostering socially responsible beliefs; and (3) teaching social‐emotional skills so as to promote healthy relationships (Frey et al.,  2005 , p. 481). The program included staff and family training manuals, a program guide and lesson‐based curricula for third‐ through sixth‐grade classrooms (Hirschstein & Frey,  2007 , p. 7).

Components at a whole school level consisted of an antibullying policy and procedures, staff training and parent meetings, all aiming at sharing understanding of bullying and its consequences and increasing adult awareness, monitoring, and involvement. At the classroom level, the proposed activities consisted of teaching friendship skills, emotion regulation skills, identifying types of bullying, teaching prevention strategies and peer group discussion. The aim was to improve peer relations and reduce the risk of victimization, assess level of safety and recognize, report and refuse bullying. At the individual level, students involved in bullying were approached and coached based on the “Four‐A Responses”: affirm behavior, ask questions, assess immediate safety and act.

The S to R training manual consisted of an instructional session for all school staff and two in‐depth training sessions for counselors, administrators, and teachers. There were also videos accompanying the program. With regard to staff training, there were two levels of training: all school staff received an overview of the program goals and principal aspects of the program (program guide). Teachers, counselors, and administrators received additional training in how to coach students involved in bullying, based on behavioral skills training, cooperative learning and role‐playing.

The student curriculum comprised skills and literature‐based lessons delivered by third‐ through sixth‐grade teachers during a 12–14‐week period. The intervention consisted of 10 semi‐scripted skills lessons with topics such as joining groups, distinguishing reporting from tattling and being a responsible bystander.

Finally, with regard to the parent intervention, administrators informed parents about the program and the school's antibullying policy and procedures. Parents could also benefit from other resources such as letters provided to them and newsletters describing whole‐school antibullying activities undertaken at school.

6.61. Strengths in Motion (SIM)

The SIM (Rawana et al.,  2011 ) program was a strength‐based whole school antibullying intervention. There were several components involved in the program, all of which centered around a strength‐based approach. This technique involves highlighting and enhancing individuals' strengths in order to develop positive mental health (Duckworth et al.,  2005 ). In the context of the present evaluation, Rawana et al. ( 2011 ) requested that each participating school allocated one room as a designated intervention resource room. In the first instance, this room acted as a “Good Start Centre” (p. 287) where new students to the school were provided with two half‐day orientation sessions prior to starting school. Part of these orientation sessions was individualized strength assessments. It was predicted that by providing new students with guidance on how to best use their strengths to integrate successfully into school life the likelihood of future bullying and victimization would be reduced.

The second use of the intervention room was as a “Cool Down & Prevention,” where students experiencing behavioral or emotional problems could go to calm down. Staff were on hand to prevent the behaviors from escalating and offer helpful advice. The room also acted as an alternative to suspension from school, whereby students could be mandated to spend a certain number of days in the “Good Choices Room.” An ambassador's club for students identified as being at high risk for bullying perpetration or victimization was also held in the resource room. Finally, mental health professionals provided student and parent workshops and staff received tailored training on the strength‐based approach to bullying prevention and intervention.

6.62. Take the LEAD (TTL)

The TTL (Domino,  2011 ,  2013 ) program was designed to increase the social competencies of participants in order to reduce bullying behaviors. The intervention is based on SEL and PYD theories.

Various social and emotional skills are targeted during the 16‐weekly lesson curriculum, including: (1) Self‐awareness; (2) Self‐management; (3) Social‐awareness; (4) Relationship skills; (5) Decision making; (6) Problem solving; and (7) Leadership. Trained teachers taught TTL lessons during normal class periods on a weekly basis. Participating teachers were trained on the skill‐based curriculum by the developers of the TTL program. During training, teachers were taught about specific learning objectives and goals of the intervention program, and also about the lesson plans and activities involved in “Take the LEAD.” Information evenings for parent were also held as part of the TTL intervention and aimed to raise parents' awareness of key social‐emotional issues.

Each of the sixteen TTL lessons involved specific learning objectives and goals. Lessons involved a combination of knowledge and skill development and an application component, so that participants were given the opportunity to apply skills in real‐world settings. For example, the “Communication skills” lesson aimed to “explore elements of communication that enhance interpersonal skills and foster positive relationships (Domino,  2013 , p. 432). During this lesson students brainstormed ideas about effective and positive communication techniques and were then required to practice these skills (e.g., eye contact, active listening and showing empathy) in pairs. Finally, participants were required to practice these techniques in an interview with a classmate, and later with a parent.

6.63. *Toronto antibullying program

The Toronto antibullying program was inspired by the OBPP (Pepler et al.,  2004 , p. 125). It was based on the understanding that bullying is a problem that extends far beyond the individual children; it involved the peer group and the teachers, as well as the parents of children (Pepler et al.,  2004 , p. 127). The program included several preventive elements implemented at the school, parent, and classroom levels, as well as additional work with specific students involved in bullying as perpetrators or victims.

The level of implementation of the program varied across the intervention schools. However, in all intervention schools three critical elements were found: staff training, codes of behavior and improved playground supervision. At the school level an emphasis was placed on developing a positive code of behavior among students, engaging teachers, and promoting positive playground interactions. At the parent level, information nights were held during which parents were informed about the problem of bullying in their school. Also, information about the program and its objectives was sent home. At the classroom level, children were involved in developing classroom rules against bullying. Further classroom activities aimed to change students' attitudes and to promote healthy relationships among peers. At the individual level, children involved in bullying as perpetrators or victims received specialized intervention through consultation and though engaging their parents. Follow‐up monitoring of these cases helped school authorities to establish that bullying incidents were terminated or discontinued.

6.64. *Transtheoretical‐based Tailored antibullying program

This antibullying initiative involved “transtheoretical‐based tailored programs that provided individualized and interactive computer interventions to populations of middle and high school students involved in bullying as bullies, victims and/or passive bystanders” (Evers et al.,  2007 , p. 398). The intervention involved only three 30‐min computer sessions during the school year for the students and a 10‐page manual for staff and parents with optional activities. According to the program designers, the transtheoretical model is “a theory of behavior change that applies particular change processes like decision‐making and reinforcement to help individuals progress at particular stages of change” (Evers et al.,  2007 , p. 398).

Intervention materials included the “Build Respect, Stop Bullying” program, which is a multicomponent, internet‐based computer system (Evers et al.,  2007 , p. 402). Students initiated the program by running a multimedia CD which brought them to the program website. Students could use the program by creating a login name based on personal information and a password. Once the students registered for the program, logged in and consented to be involved in the intervention study, they were given instructions on how to proceed. This multi‐media program also included short movies (videos) of students giving testimonials about bullying (Evers et al.,  2007 , p. 403).

Other elements of the program included: (1) a 10‐page family guide, sent to children's homes, which provided brief information about the multi‐media program and its relation to the antibullying initiative; and (2) a 10‐page staff guide, which included general information about bullying and how to support student change, classroom activities and information on how to work with parents. Teachers were not provided with any training.

6.65. Utrecht Healthy Schools

The Utrecht Healthy Schools program was a comprehensive educational program that targeted adolescent health behaviors (Busch et al.,  2013 ). The integrated program aims to improve various different health‐related behaviors exhibited by Dutch secondary school students, such as, nutrition, exercise, sexual health, substance and alcohol use, smoking behaviors, bullying, and excessive use of television, gaming and Internet use. The program was implemented as a whole‐school approach and consisted of five key components.

First, participating schools implemented a “healthy school” policy outlining a zero‐tolerance attitude toward risky or violent behaviors, such as alcohol use, smoking or bullying. Second, the program aimed to create a healthy school environment by offering healthy options in the canteen, removing vending machines, ensuring proper sports facilities, hosting alcohol‐free school parties and implementing a smoke‐free school yard. In the third instance, the program aimed to involve parents in intervention activities by providing parent workshops and/or take‐home activities for students. Finally, curriculum materials focused on personal skill development and the program aimed to incorporate public health services into the intervention program.

6.66. *Viennese Social Competence Training program (ViSC)

The ViSC aimed to provide students “with systematic theoretically‐based guidance in becoming responsible and competent actors in conflict situations” (Atria & Spiel,  2007 ; Yanagida et al.,  2019 ). It was specifically designed for disadvantaged adolescents aged fifteen to nineteen who were considered at risk for future problems (Atria & Spiel,  2007 , p. 179). The theoretical basis of the programs drew its main ideas from social information processing theory and from research that approached the problem of bullying as a group phenomenon (Gollwitzer et al.,  2006 , p. 126).

The ViSC program consisted of thirteen lessons which were divided into three phases: (1) impulses and group dynamics; (2) reflection; and (3) action. The first phase, entitled “impulses and group dynamics,” consisted of six lessons and the main aim was to enhance students' competence in dealing with critical situations by teaching them how to look at social situations from different perspectives using vignette stories, discussions and role‐plays. The second phase, reflection , involved one lesson during which pupils reflected on what had been learned in the first phase of the program.

The last phase, action , consisted of six lessons during which the trainer asked students to define how they wanted to benefit from the remaining lessons. The trainer collected students' individual ideas, evaluated them and—along with the students—put them in practice in alignment with the global goal of the program: enhancing pupils' social competence. The third phase of the program was flexible and it could involve several projects suggested by pupils such as a movie production, a work of art, the organization of a party, and so on. This flexibility was allowed and was, in fact, a main feature of ViSC because organizing such projects “involves a variety of critical situations, in which alternative, nonaggressive response options can be probed, rehearsed, and evaluated for success” (Gollwitzer et al.,  2006 , p. 126).

Based on the design of the program, the training of students was conducted by specialist trainers, not their teachers. The trainers participated in instruction workshops and were also supervised during the training by the ViSC developers' team at the University of Vienna (Gollwitzer et al.,  2006 , p. 127). According to the principles of the program, it was essential for the trainer to avoid receiving any information about individual students offered by teachers; students' assessments should be based on standardized diagnostic measures (Atria & Spiel,  2007 , p. 184). Moreover, the training was conducted during regular class time and teachers were advised to attend the lessons, so that the program was taken seriously by the students. ViSC has been implemented and evaluated three times: by Gollwitzer (2005), by Atria and Spiel ( 2007 ) and by Gollwitzer et al. ( 2006 ).

6.67. Youth‐led program

The Youth‐led program (YLP; Connolly et al.,  2015 ) was a generalized middle school violence prevention program. This program was developed by a community agency, and involved training high school students to lead violence prevention workshops with middle school students in order to increase the latter's knowledge and attitudes of peer aggression and victimization.

Experienced mental health professionals were employed to select and supervise male and female high school students that would become “youth leaders.” These students received training in afterschool sessions on skills and knowledge of peer aggression. Topics covered included bullying perpetration and victimization, but also peer aggression, violence, and harassment.

The final sessions of this training required the youth leaders to create two individualized presentations; one covering bullying and the other discussing general aggression. Mixed gender pairs of youth leaders then conducted these presentations in middle school classrooms under the supervision of a mental health worker. These presentations lasted for approximately 45 min each.

6.68. *Youth Matters

The Youth Matters program used “a curricular and a modified systemic approach to bullying prevention” (Jenson & Dieterich,  2007 , p. 287). The aim of the curriculum was to strengthen peer and school norms against antisocial behaviors by addressing critical issues (issue modules) such as the difference between teasing and bullying, building empathy, risks and norms surrounding aggression and so on. The curriculum also aimed to promote skills (skill modules; structured skills training sessions) that students could use in order to stay safe at school, cope with bullying, enhance their social skills and improve their peer relationships. To address systemic issues associated with bullying, curriculum modules terminated with the development of classroom or school‐wide projects, which placed emphasis on the negative consequences of bullying for students.

The curriculum consisted of 10‐session modules. Each module included a 30–40‐page story, the content of which was directly linked to the structured skills training sessions. When looking at the implementation of the program, all curriculum materials were “language sensitive”: translated into Spanish for use in the three Spanish‐speaking classrooms included in the evaluation. Youth Matters curriculum modules were offered to fourth and fifth graders. According to Jenson and Dieterich ( 2007 , p. 287), grades 4 and 5 were selected “based on an appropriate fit between developmental ability and curricula.”

The Youth Matters program was based on a theoretically grounded curriculum. The curriculum was based on theoretical constructs derived from the Social Development Model. The latter integrated perspectives from three theories (i.e., social control theory, social learning theory and differential association theory) and proposed that four factors inhibit the development of antisocial development in children. These were: (1) bonding or attachment to family, schools and positive peers; (2) belief in the shared values or norms of the above‐mentioned social units; (3) external constraints or consistent standards against antisocial behavior; and (4) social, cognitive and emotional skills that can be seen as protective tools for children to solve problems and perform adequately in social situations. The Youth Matters curriculum addressed each of these four core areas.

6.69. Zero program

The Zero antibullying program is based on the idea that bullying is predominately a version of proactive aggression (Roland et al.,  2010 ). The program aims to create a school environment that prevents these forms of proactive aggression. The intervention places the majority of responsibility for bullying prevention and intervention with the adults within the school environment (Roland et al.,  2010 ). School staff were required to define clear standards of positive prosocial behavior among the students and to ensure that these standards are met. Thus, the adults within the school context adhere to a “zero tolerance” policy toward bullying. Another key feature of the intervention is that students are instructed to treat all school property appropriately and respectfully and the intervention philosophy is carried into classroom activities and standards also.

During the intervention, class teachers engage their respective classes in active discussions about issues relating to bullying in adherence with the intervention guidelines. The preventative function of the Zero program takes both a direct and indirect approach (Roland & Galloway,  2004 ). Teachers are also expected to be vigilant and visible in school corridors and playgrounds during nonclass time and follow intervention procedures when dealing with specific instances of bullying (Roland et al.,  2010 ). When particular instances of bullying are identified, the victim is first approached and takes part in a few sessions with trained staff being comforted and assured. Parental involvement also occurs at this point. Finally, the perpetrators are invited to attend meetings and conflict resolution occurs under a restorative justice model.

6.70. Zippy's Friends

Zippy's Friends is a universal school‐based program for children aged 6–8 years old (Holen et al.,  2013 ; Mishara & Ystgaard,  2006 ). The overarching aim of the program is to develop and improve participants' coping strategies in order to reduce and prevent psychological problems. Zippy' Friends has been funded by the global suicide prevention organization “Befrienders International,” and is now distributed internationally by the nonprofit group “Partnership for Children.”

The intervention is delivered over the course of 24 weekly lessons, that are implemented by classroom teachers. The program is based around six stories of the imaginary character “Zippy,” three children, and their families and friends. A structured curriculum outline for each lesson allows participants to engage and discuss the various themes that emerge in each of the stories. Themes that are incorporated include: emotions; communication; friendships; conflict resolution; loss and change.

Teachers are provided with a detailed manual for the program and are required to guide their classrooms through the intervention while also encouraging active engagement with the content. Typical activities that are involved in the Zippy's friends program include: drawing, role‐playing, performing exercises, play and dialogue.

7. RESULTS OF SYSTEMATIC REVIEW

In addition to the newly identified studies ( n  = 88), primary evaluations ( n  = 53) discovered by Farrington and Ttofi ( 2009 ) are also included in the present systematic review, giving a total of 141 studies. However, this updated systematic review has excluded evaluations that used an “other” experimental‐control design ( n  = 13). Next, a detailed explanation is provided about studies which were excluded from the current review and justifications for this decision.

7.1. Studies excluded because of missing information

A certain amount of statistical information is needed in order to produce meaningful effect sizes in a meta‐analysis. We estimated an antibullying program's effectiveness as the difference between the experimental and control groups on bullying outcomes, either measured as the percentage of bullies/nonbullies or victims/nonvictims or based on mean scores on measurement instruments before and after implementation of the intervention.

However, 21 studies identified by our systematic review did not present sufficient effect size information, and so the primary authors of these publications were contacted. We were able to obtain relevant information for the majority of these studies, but three authors were unable to provide required statistics and seven did not respond to our email communication.

Thus, 10 studies had to be excluded from our meta‐analysis because of a lack of information regarding quantitative outcomes. These relate to: Gradinger et al. ( 2015 ); Harpin ( 2011 ); Kyriakides et al. ( 2014 ); Lewis et al. ( 2013 ); Lishak ( 2011 ); Low and Van Ryzin ( 2014 ); van der Ploeg et al. ( 2016 ); Sahin (2012); Schroeder et al. ( 2012 ); and Wurf (2010). In the previous review by Farrington and Ttofi ( 2009 ), 44 out of 53 evaluations provided sufficient information on quantitative outcomes.

7.2. Studies excluded because of nonindependent samples

One further stipulation of a meta‐analysis is that the final samples must be independent of one another (Borenstein et al.,  2009 ; Ellis,  2010 ). Overlapping samples are statistically dependent, and thus the variance of the summary effect size produced by the meta‐analysis would be under‐estimated (Wilson,  2010 ). Therefore, before conducting our meta‐analysis we ensured that all samples were independent of one another.

This issue of nonindependent samples was particularly relevant for the multiple evaluations of the KiVa antibullying program. Our thorough systematic searches identified 16 potentially includable studies presenting evaluation data from implementation of the KiVa program (i.e., Ahtola et al.,  2012 ,  2013 ; Garandeau, Lee, et al.,  2014 , Garandeau, Poskiparta, et al.,  2014 ; Haataja et al.,  2014 ; Hutchings & Clarkson,  2015 ; Kärnä et al.,  2011a ,  2011b ,  2013 ; Nocentini & Menesini,  2015 ; Noland,  2011 ; Sainio et al.,  2012 ; Salmivalli et al.,  2012 ; Williford et al.,  2012 ,  2013 ; Yang & Salmivalli,  2015 ). For a description of each of these studies, see Table  7 .

Description of KiVa studies

* Included in meta‐analysis.

However, following further screening, only four of the aforementioned studies were subsequently included in the systematic and meta‐analytic review (i.e., Kärnä et al.,  2011a ,  2011b ,  2013 ; Nocentini & Menesini, 2016). These four studies presented independent results of the KiVa program from the initial nationwide evaluation in Finland. Kärnä et al. ( 2011a ) used an age cohort design with adjacent cohorts and reported the initial results from the nationwide implementation in Finland. Second, Kärnä et al. ( 2011b ) reported the results from the RCT with Finnish students in grades 4–6, and Kärnä et al. ( 2013 ) reported results for students in grades 1–3 and 7–9. In addition, Nocentini and Menesini (2016) reported the results of the implementation and evaluation of KiVa in Italian schools. The remaining 12 publications relating to the KiVa program utilized data from the RCT evaluation in Finland (i.e., Kärnä et al.,  2013 or Kärnä et al.,  2011b ) but explored different facets of the program's effectiveness.

Four studies identified in our systematic searches replaced evaluations included in the earlier review. For example: (1) Menard and Grotpeter ( 2014 ) was a continuation of the Menard et al. ( 2008 ) evaluation; (2) Cross et al. ( 2011 ) was a republication of the Cross et al. ( 2004 ) evaluation included in the previous review; (3) Jenson et al. ( 2013 ) and Jenson et al. ( 2010 ) presented data from additional follow‐up points to the Jenson et al. ( 2007 ) evaluation; and (4) Frey et al. ( 2009 ) used an age cohort design to evaluate follow‐up effects from the earlier Frey et al. ( 2005 ) study. In cases such as these, the most recent publication, or the publication with the most statistical information, was included in the meta‐analysis.

Ten studies (published both before and since 2009) were identified as reporting the effectiveness of an antibullying program from the same sample, or were repeat publications of earlier studies (e.g., DeRosier,  2004 and DeRosier & Marcus,  2005 ; Domino,  2011 and Domino,  2013 ; Espelage et al.,  2013 and Espelage et al.,  2015 ; Jenson et al.,  2013 and Jenson et al.,  2010 ; and Menesini et al.,  2012 ; Study 2 and Palladino et al.,  2012 ). In these instances, the most recent publications were selected, and as a result, five studies were excluded from the meta‐analysis.

7.3. Included studies

Therefore, 128 studies are included. Table  5 summarizes the intervention programs and methodological components of the 79 newly identified studies that are included in the present systematic review. For details of the remaining 49 studies please refer to Farrington and Ttofi ( 2009 ).

7.4. Moderator analysis

The following moderators were selected a priori for further analysis, under the descriptive label (i.e., location of intervention, publication type, publication year), design label (i.e., evaluation method and unit of allocation/randomization), and the program heading (i.e., name of intervention, COI, and program specificity). Results of these moderator analyses analogous to the analysis of variance (ANOVA) are presented in Sections 8.5.1 to 8.5.7 of the present report.

7.4.1. Evaluation method

The primary moderator chosen for further analysis was evaluation method. Specifically, whether the evaluation was conducted using a RCT, quasi‐experimental with before and after measures (BA/EC) or age cohort (AC) design.

Overall, in relation to bullying perpetration outcomes, 36 evaluations used RCT designs, 31 used BA/EC designs and 14 used age cohort designs. However, due to some evaluations reporting data for multiple independent samples, a total of 40 effect sizes were estimated for bullying perpetration outcomes from RCT designs. A further 36 were estimated from BA/EC designs and 14 effect sizes came from evaluations using age cohort designs.

For bullying victimization outcomes, overall, 33 evaluations used RCT designs that gave 37 independent effect sizes for bullying victimization and 37 evaluations used BA/EC designs and gave 42 independent effect sizes. Similar to perpetration outcomes, 14 evaluations used age cohort designs to evaluate the effect of antibullying programs on bullying victimization outcomes.

7.4.2. Location of intervention

Evaluations included in the present analysis were conducted in many different countries around the world. However, there were only a few countries in which multiple evaluations of antibullying programs had been published.

Specifically, in the following countries only one evaluation was included in the present report: Austria (i.e., Yanagida et al.,  2019 ); Brazil (i.e., Silva et al.,  2016 ); China (i.e., Ju et al., 2009); Czechoslovakia (modern day Czech Republic and Solvakia; i.e., Rican et al.,  1996 ); Hong Kong (i.e., Wong et al.,  2011 ); Ireland (O'Moore and Milton,  2004 ); Malaysia (i.e., Yaakub et al.,  2010 ); Romania (i.e., Trip et al.,  2015 ); Sweden (i.e., Kimber et al.,  2008 ); Switzerland (Alsaker & Valkanover,  2001 ); South Africa (Meyer & Lesch,  2000 ); and Zambia (Kaljee et al.,  2017 ).

If these evaluations were to be included in further moderator analysis, we would be examining the differences based on only one sample and effect size. Therefore, moderator analysis was conducted only between locations in which multiple evaluations of antibullying programs had been conducted.

So, of the 100 evaluations included in our meta‐analysis of school‐based antibullying programs, the majority (80 for perpetration, 84 for victimization) were conducted in one of 12 different countries. With respect to bullying perpetration outcomes, these countries were as follows: Australia ( n  = 2); Canada ( n  = 6); Cyprus ( n  = 3); Finland ( n  = 6); Germany ( n  = 5); Greece ( n  = 2); Italy ( n  = 11); Netherlands ( n  = 3); Norway ( n  = 8); Spain ( n  = 3); UK ( n  = 4); and United States ( n  = 26). With respect to bullying victimization outcomes, these countries were as follows: Australia ( n  = 3); Canada ( n  = 7); Cyprus ( n  = 3); Finland ( n  = 6); Germany ( n  = 4); Greece ( n  = 2); Italy ( n  = 10); the Netherlands ( n  = 3); Norway ( n  = 7); Spain ( n  = 3); UK ( n  = 6); and United States ( n  = 28).

7.4.3. Publication type and year

Overall, the majority of evaluations were published in peer‐reviewed journal articles, for both bullying perpetration ( n  = 67) and bullying victimization ( n  = 72) outcomes. Two evaluations were published in chapters of edited books and both reported effects of a program on both bullying victimization and perpetration. No evaluations identified were published as entire books. Moreover, 12 unpublished dissertations were identified that published evaluation data for bullying perpetration and bullying victimization outcomes. Data was also retrieved for both outcomes from three governmental reports. Four of the effect sizes included in the present report were estimated from data emailed to authors (M. M. T. and D. P. F.) in preparation of the previous Campbell report (i.e., Farrington & Ttofi,  2009 ).

We also categorized included evaluations according to whether they were included in the previous report (i.e., “2009” studies), or only included in the present report (i.e., “2016” studies). In relation to bullying perpetration outcomes, 37 studies were coded as 2009 studies and 53 studies were coded as 2016 studies. Similarly, more studies were coded as 2016 ( n  = 54) studies in comparison to 2009 ( n  = 39) studies for bullying victimization outcomes.

7.4.4. Intervention program

We found that very few specific antibullying programs had been implemented and evaluated more than once using independent samples. Sixty‐five different school‐based bullying intervention and prevention programs were included in our meta‐analysis, but only eight were repeatedly evaluated. Moderator analysis with respect to the specific intervention program therefore, focused on programs that had been repeatedly evaluated.

In relation to reducing bullying perpetration outcomes the intervention programs thus included in our moderator analysis were: BPYS ( n  = 3; e.g., Menard & Grotpeter,  2014 ); fairplayer.manual ( n  = 2; e.g., Bull et al.,  2009 ); KiVa ( n  = 6; Kärnä et al.,  2011b ); NoTrap! ( n  = 4; e.g., Menesini et al.,  2012 ); Second Step ( n  = 3; e.g., Espelage et al.,  2015 ); Steps to Respect ( n  = 2; e.g., Frey et al.,  2005 ); ViSC ( n  = 5; e.g., Yanagida et al.,  2019 ).

Similarly, these interventions were included in our moderator analysis in relation to bullying victimization outcomes with the exception of the fairplayer.manual program. This intervention was evaluated twice only in relation to bullying perpetration outcomes.

Additionally, multiple evaluations of the OBPP were included in our meta‐analysis. Overall, 12 independent evaluations of this intervention were included in our analysis in relation to bullying perpetration and victimization outcomes. These are included in our moderator analysis as a collective subgroup and also as further subgroups. Evaluations of the OBPP conducted in the United States (perpetration n  = 6; victimization n  = 7) and those conducted in Norway (perpetration n  = 5; victimization n  = 5) were included in the moderator analysis separately. There was one evaluation of the OBPP conducted in Malaysia is included in the overall category ( n  = 12).

7.4.5. Unit of allocation/randomization

Systematic review findings showed that one consistent issue with included intervention programs was that the unit of allocation of participants, or clusters of participants, was different to the unit of analysis in most evaluations. Age cohort designs were omitted from this moderator analysis as the unit of allocation was largely unclear due to the logistics of this experimental design.

The majority of RCT and BA/EC evaluations assigned schools to experimental conditions (perpetration n  = 44; victimization n  = 47) yet the unit of analysis was individual students. A number of evaluations (perpetration n  = 19; victimization n  = 15) assigned classes to experimental conditions yet the unit of analysis was individual students. Less than 10 evaluations (perpetration n  = 7; victimization n  = 9) included assigned students to experimental and control conditions. One study randomly assigned districts to experimental conditions, and information was not available for five studies in relation to bullying perpetration outcomes and four studies in relation to bullying victimization.

7.4.6. Conflict of interest

In the present report, 40 studies were categorized as high COI. A large number of studies (perpetration n  = 36; victimization n  = 39) were considered low COI, and 14 were categorized as possible COI. Information concerning COI was unavailable for 4 evaluations in relation to bullying perpetration outcomes.

7.4.7. Program specificity

Overall, a small number ( n  = 11) of studies included in our analysis were coded as low on the program specificity variable. The vast majority of evaluations were considered highly specific (i.e., were mostly concerned with only bullying behavioral outcomes; n  = 59). Additionally, 18 studies were categorized as medium in relation to specificity, where extra outcome variables were measured but these variables were related to bullying (e.g., school climate).

7.5. Risk of bias analysis

Figure  2 presents the results of the risk of bias analysis for each of the items on the EPOC tool and the additional items we included. The following section describes each of these categories in more detail, with examples of high‐ and low‐risk studies included. The main limitation in assessing risk of bias was the lack of information reported by primary studies. Thus, while the best effort was made to categorize each primary evaluation as being high or low risk, a large number of studies were recorded as “unclear” risk.

Risk of bias analysis results. AC, allocation concealment; AS, allocation sequence; BC, baseline equivalence on participant characteristics; BE, baseline equivalence on outcomes; BOA, blind outcome assessment; COI, conflict of interest; CP, contamination protection; ID, incomplete outcome data; SOR, selected outcome reporting

As seen in Figure  2 , the fewest studies were considered unclear risk on CP and selected outcome reporting. Furthermore, a large number of studies were considered low risk on these items.

For the purpose of analysis, the categories high, unclear, and low risk were transformed into scores of 3, 2, and 0 respectively. A continuous “risk of bias” variable was then estimated as the sum total of scores on each of the EPOC items. As such, the lowest possible score a study could be given was zero and the maximum score was 24.

Descriptive statistical analysis identified that risk of bias scores ranged from 0 to 17, with a mean score of 9.62. Meta‐regression analysis was conducted to assess the relationship between risk of bias and effect sizes. The result of this analysis is included in Section  7 of this report. The following sections provide more detail about each of the risk categories.

7.5.1. Allocation sequence

AS refers to the way in which participants, or clusters of participants, were assigned to experimental conditions. For example, low‐risk studies were those where a random number generator or another randomization software was used. In total, 30 studies were categorized as high risk on the AS item. Moreover, 29 studies were low risk and 32 were unclear risk.

7.5.2. Allocation concealment

AC item refers to whether the method of allocation was concealed from participants or not. In total, 36 studies were categorized as high risk on the AC item. A further 19 studies were considered low risk, and 34 were unclear risk.

7.5.3. Baseline equivalence: Outcome

Baseline equivalence refers to the comparability of experimental and control participants before the intervention has taken place. This item specifically refers to equivalence on relevant outcomes, in this case, school bullying perpetration and victimization. When experimental and control participants are not statistically significant at baseline then we can be more certain that any changes are a result of the intervention. Overall, 14 studies were categorized as high risk on the baseline equivalence on bullying outcomes item. A total of 54 studies were low risk and 21 were unclear risk.

7.5.4. Baseline equivalence: Characteristics

Similarly, baseline equivalence on participant characteristics increases the chance that any change is a result of the intervention, and not a confounding variable such as differential participant characteristics at baseline. Overall, 15 studies were categorized as high risk on the baseline equivalence in participant characteristics item, 64 studies were low risk, and 11 were unclear risk.

7.5.5. Incomplete outcome data

Included evaluations were required to incorporate pre‐ and post‐intervention measures of bullying (except if randomization was used). However, because of this, it is likely that there will be some attrition in primary studies. The incomplete outcome data item referred to the risk associated with differential attrition between experimental groups and/or ways in which attrition and missing cases were dealt with by primary studies. Twelve studies were categorized as high risk on the incomplete outcome data item. Additionally, 48 studies were low risk and 29 were unclear risk.

7.5.6. Blind outcome assessment

This item assesses the risk associated with any bias which may arise if outcome measurements are not conducted blindly. In other words, if the individual, or individuals, who administer and collect the measurement instruments are aware of the experimental conditions of participants at the time of measurement. Overall, 27 studies were categorized as high risk on the BOA item. Twenty studies were low risk and 43 were unclear risk.

7.5.7. Contamination protection

Risk of contamination occurs when there is a possibility that experimental and control participants may interact or encounter one another during the course of the evaluation. Thus, the effects of the intervention may “spill over” to control students and impact the results of the evaluation. In our analysis, 35 studies were categorized as high risk on the CP item, 47 studies were low risk, and 9 were unclear risk.

7.5.8. Selective outcome reporting

SOR occurs when the outcomes reported in an evaluation study differ from the outcomes of interest proposed originally. For example, if a trial protocol proposed different outcomes than those actually reported in the publication of the trial results. Two studies were categorized as high risk on the SOR item. Eighty‐four studies were low risk, and three were unclear risk.

8. META‐ANALYSIS

After accounting for missing information, studies excluded because of their methodology (i.e., “other experimental‐control” designs), and studies with overlapping samples, a total of 41 studies were excluded from the meta‐analysis. Thus, a total of 100 studies were eligible for inclusion in our meta‐analysis. Table  8 outlines the raw data from these studies used to estimate effect sizes. The Comprehensive Meta‐Analysis (CMA) software was used to estimate all summary effect sizes in the present meta‐analysis.

Raw data from included evaluations

Abbreviations: A, after; B, before; C, control; E, experimental; M , mean; N , sample size; n , group sample size.

8.1. Effect sizes

A meta‐analysis aims to estimate comparable effect sizes from multiple primary studies. The choice of effect size depends on how statistical information is reported by primary studies (Borenstein et al.,  2009 ). In meta‐analyses such as this one, the data is largely presented in continuous (e.g., means, standard deviations, sample sizes) or dichotomous (e.g., prevalence or percentages) forms (Wilson,  2010 ). Thus, primary effect sizes estimated were Cohen's d and Odds Ratios.

As previously mentioned, we aimed to estimate one effect size for each independent sample included in primary studies. Therefore, where studies reported results separately for male and female participants, or primary and secondary school students, one effect size was calculated for each group.

For primary studies that presented results as percentages or frequencies of participants identifying as either bullies or victims, the odds ratio (OR) effect size was estimated. The ORs for before and after intervention time‐points were calculated independently. The CMA™ software that we used to analyze effect sizes in the present report did not allow us to enter raw data for before and after time‐points for primary studies that reported dichotomous outcomes separately. Thus, we were unable to use this software to calculate a pre‐post intervention estimate for these studies. Hence, these calculations were carried out manually, 5 by the first author, using the method outlined by Farrington and Ttofi ( 2009 ).

Cohen's d was estimated for primary studies when results were reported in the form of continuous data. Cohen's d is estimated as the difference between experimental and control means divided by the pooled standard deviation (Wilson,  2010 , p. 184). Effects were assigned a positive direction in cases where bullying was less in the experimental group compared to the control group or where the reduction in bullying outcomes was larger in the experimental group in comparison to the change in the control group. Following this logic, a negative effect was found when there was: (1) a larger reduction in the control group compared to the experimental group; or (2) there was no change or increase in bullying perpetration/victimization in the experimental group but a reduction or smaller increase in the control group.

For comparability, all effect sizes were converted to ODs. Summary mean effects for bullying perpetration, bullying victimization, and for each of the moderator subgroup are thus reported as odds ratios. In the present review, odds ratios greater than one represent a positive, or desirable, intervention effect. Namely, a reduction of bullying in the experimental group, that is comparably larger than the change in bullying in the control group. Therefore, the change is attributed to have occurred because of the intervention program. Similarly, odds ratios less than one represent a negative, or undesirable, intervention effect and odds ratios that equal one represents a null effect.

8.2. Corrections for clustering

As the present review aims to evaluate the effectiveness of school‐based antibullying programs, cluster‐randomized trials were included. Clustering is a common phenomenon in educational evaluations (Donner & Klar,  2002 ), and occurs when “clusters,” not individuals, are randomly assigned to experimental conditions (Higgins et al.,  2011 ). In other words, primary studies sometimes assigned classes or schools to intervention and control conditions, rather than individual students.

Often this approach is utilized in evaluation studies to reduce treatment contamination and increase administrative convenience (Donner et al.,  2001 ). However, one of the main issues with incorporating cluster‐randomized trials in a meta‐analysis is that participants within a cluster are likely to be more homogeneous than participants in another cluster (Higgins et al.,  2011 ). Thus, the variance of estimates of treatment effectiveness will be under‐estimated (Donner & Klar,  2002 , p. 2974). Clustering could occur for several reasons in studies included in the present report. For example: (1) classes of children, not individual children, were e randomized to intervention or control condition; (2) the intervention was implemented at the classroom level (i.e., to a class or group of children at one time); or (3) the intervention was targeted at teachers, who were trained to implement the intervention in their respective classrooms.

Therefore, effect sizes in the present meta‐analysis were corrected for the inclusion of clusters in primary studies. This is achieved by estimating a design effect:

where M represents the mean cluster size in each study (e.g., the mean number of students per classroom 6 ) and the ICC is the intraclass correlation coefficient.

The ICC is rarely reported by primary studies (Higgins et al.,  2011 ; Valdebenito et al.,  2018 ). Based on Murray and Blitse ( 2003 ), and subsequently the strategy followed by Farrington and Ttofi ( 2009 ), an ICC of 0.025 was assumed in the current meta‐analysis. The variances of effect sizes were then multiplied by this design effect estimated for each study. In the present meta‐analysis, there were only four studies where corrections for clustering were not required. Three studies (i.e., Berry & Hunt,  2009 ; Knowler & Frederickson,  2013 ; Meyer & Lesch,  2000 ) randomly assigned participants to experimental conditions, and Elledge et al. ( 2010 ) described an intervention that was not implemented in a classroom (i.e., the intervention occurred in one‐on‐one sessions with victims of bullying).

8.3. Computational models

The results of our meta‐analysis are presented using two different models. First, we will report the results as estimated using a random effects model that weights studies, largely in proportion to the between‐study variance and accounting for sampling error, thus allowing for the natural variation that occurs between primary studies (Borenstein et al.,  2009 ). We also present the results under the MVA model (Jones, 2005; Farrington & Welsh,  2013 ). which uses the same estimation of a mean effect size as the fixed effects model in that it assigns greater weight to larger evaluations, but also accounts for the between‐study heterogeneity. The MVA model takes account of the heterogeneity of effect sizes to fit the data exactly and yields the same mean effect size as a fixed effect model, but with and increased confidence interval. 7

Farrington and Welsh ( 2013 ) have argued that larger evaluations should be given more weight, and that adding to the variance of effect sizes in order to reduce the heterogeneity is not an optimal method of estimating the weighted mean effect size. When there is considerable heterogeneity in effect sizes, all studies tend to be given much the same weighting in a random effects model. Therefore, several effect sizes from independent samples in one study (e.g., a multisite evaluation) will have a greater weight in the random effects model than in the fixed effects model.

Comparing six models of estimating mean effect sizes for the impact on CCTV on crime rate, Farrington and Welsh ( 2013 ) found that five of the six models produced very similar mean odds ratio effect sizes, with the exception of the random effects model. In this case the random effects model estimated a much higher mean odds ratio (Farrington & Welsh,  2013 , p. 11).

The MVA model is suggested as an alternative approach that overcomes the issues of the random effects model. This technique can be seen as an adjustment to the fixed effects model and combines both the strengths of the fixed effects model (i.e., larger studies = larger weights) and the random effects model (i.e., adjusting for highly probable between‐study variance), and has been used in several meta‐analyses from both the behavioral sciences (e.g., Portnoy & Farrington,  2015 ; Ttofi et al.,  2016 ; Zych, Baldry, et al.,  2019 ; Zych, Viejo, et al.,  2019 ) and medical sciences, where this is known as the “Shore adjustment” (e.g., Ayieko et al.,  2014 ; Carlos‐Wallace et al.,  2016 ; Erren et al.,  2009 ; Steinmaus et al.,  2008 ).

A full review of the strengths and limitations of this model is beyond the scope of the current review. Therefore, in our current meta‐analysis we report mean effect sizes for the impact of antibullying programs on bullying perpetration and bullying victimization using both the random effects model and the MVA model. In later sections, we discuss the differences in the weighted mean effect sizes according to the model chosen.

8.4. Moderator analysis

In traditional empirical research when one wishes to compare two mean values to evaluate the difference between two participants, or two groups of participants, a t test is the standard statistical test. In meta‐analysis, we want to compare subgroups of studies rather than sub‐groups of individuals, so the analysis is slightly different. We followed guidelines provided by noted meta‐analysts for this type of analysis (Borenstein et al.,  2009 ; Lipsey & Wilson,  2001 ).

Our approach involved two steps: (1) computing the mean effect and variance for each subgroup; and (2) comparing the mean effects between subgroups (Borenstein et al.,  2009 , p. 152). This approach has been used previously by researchers to conduct similar analyses (e.g., Kaminski et al.,  2008 ; Ttofi & Farrington,  2011 ).

Comparing the mean effect sizes for subgroups involves a method that is analogous to a one‐way ANOVA in primary research (Hedges,  1982 ; Lipsey & Wilson,  2001 ; Wilson, 2002). The meta‐analyst creates mutually exclusive categories of primary studies and then compares the between‐studies ( Q B ) and the within‐studies ( Q W ) variance.

The between‐studies heterogeneity is the value used to evaluate whether the difference between subgroups is statistically significant (i.e., whether the difference in weighted mean effect sizes for subgroups is, at least partially, explained by the relevant intervention component). Similar to a one‐way analysis of variance, this approach partitions the variance and compares the variability between‐groups. The following formula is used to estimate the Q B :

The degrees of freedom for the between‐studies heterogeneity is estimated as j  − 1 and the statistical significance is determined using a χ 2 distribution. As Q B is estimated using the weights assigned to observed effect sizes, the value will vary between the fixed effects model and the random effects model. Q B is not reported for comparisons of subgroups with very unequal numbers of studies (e.g., location of the evaluation). Under the MVA model, the heterogeneity between groups is estimated by dividing the fixed effects Q B by Q/df . The present report presents results from moderator analysis under both the random effects and MVA models.

8.5. Meta‐regression analysis

CMA™ version 3 software was used to conduct meta‐regression analysis to explore the relationship between continuous moderator variables and perpetration and victimization outcomes. Weighted regression analysis (Lipsey & Wilson,  2001 ) were used to explore which moderators were independently related to school bullying perpetration and victimization. Meta‐regression analyses were only conducted for continuous moderator variables.

Meta‐regression analyses were computed under a fixed effects model, and the standard error of regression coefficients were adjusted using the MVA model. The Q and df of Q for the mean summary effect sizes for subgroups were used to adjust the standard error to reflect between‐study variance.

9. RESULTS OF META‐ANALYSIS

In total, 100 studies were included in our meta‐analysis of the effectiveness of school‐based antibullying programs. From these evaluations, we were able to estimate 103 independent effect sizes. These are presented for bullying perpetration and bullying victimization outcomes in Tables  8 and  9 , respectively. The majority of these effect sizes were estimated from studies that used RCT designs ( n  = 45 effect sizes) or BA/EC designs ( n  = 44 effect sizes). We estimated the remaining 14 effect sizes from age cohort designs.

Meta‐analysis results: School‐bullying perpetration outcomes

Abbreviations: BA/EC, before‐after/experimental control designs; CI, confidence intervals; MVA, multiplicative variance adjustment; OR, odds ratio; RCT, randomized controlled trial; Sig, statistically significant.

9.1. School‐bullying perpetration outcomes

Overall, we found that antibullying programs significantly reduced bullying perpetration under both computational models of meta‐analysis. The effect sizes for each evaluation are presented in Table  9 . The mean summary effect sizes were similar under both the multivariance adjustment model (MVA: OR = 1.324; 95% CI 1.27–1.38; z  = 13.4; p  < .001; I 2  = 81.42) and the random effects model (RE: OR = 1.309; 95% CI: 1.24–1.38; z  = 9.88; p  < 0.001; τ 2  = 0.044).

This result indicates that participants in primary studies who received an antibullying intervention were less likely to report engaging in bullying others after completing the program in comparison to control students who did not partake in the program.

Analysis of the funnel plot (Figure  3 ) suggests that publication bias is not present, as studies are symmetrically distributed around the mean effect size. In addition, point estimates did not vary using Duval and Tweedie's trim and fill procedure under a random effects model (in both cases: OR = 1.308; 95% CI 1.240–1.380). Based on these results, it was reasonable to assume that publication bias was not likely.

Publication bias analysis: school‐bullying perpetration

9.2. School‐bullying victimization outcomes

Overall, we found that antibullying programs significantly reduced bullying victimization under both computational models of meta‐analysis. The effect sizes for each evaluation are presented in Table  10 . The mean summary effect sizes were very similar under both the multivariance adjustment model (MVA: OR = 1.248; 95% CI 1.21–1.29; z  = 12.06; p  < .001; I 2  = 78.327) and the random effects model (RE: OR = 1.244; 95% CI: 1.19–1.31; z  = 8.92; p  < 0.001; τ 2  = 0.032).

Meta‐analysis results: School‐bullying victimization outcomes

This result suggests that students who participated in an antibullying program were significantly less likely to report being bullied by others after receiving the intervention in comparison to students who did not receive the intervention.

The funnel plot in Figure  4 indicates that no publication bias is present in analysis of bullying victimization effect sizes, as the studies fall symmetrically around the mean effect size. Duval and Tweedie's trim and fill procedure highlighted some minor differences between observed effect sizes (OR = 1.245; 95% CI 1.186–1.306; Q  = 460.97) and adjusted effect sizes (OR = 1.241; 95% CI 1.182–1.303; Q  = 473.43). However, this difference is negligible. Based on these results, it was reasonable to assume that publication bias was not likely.

Publication bias analysis: school‐bullying victimization

9.3. Analysis of heterogeneity

In a meta‐analysis, heterogeneity ( Q ) is the between‐study spurious variance that occurs partly because of true variation in effect sizes, but also as a result of random error (Borenstein et al.,  2009 ). Heterogeneity is estimated as the excess variation that exists when we compare the total amount of between‐study variance and within‐study random error.

In the present meta‐analysis, there was significant heterogeneity between studies for both bullying perpetration ( Q  = 323.392; df  = 85; p  < 0.001; I 2  = 73.716) and bullying victimization ( Q  = 387.255; df  = 87; p  < 0.001; I 2  = 77.534) outcomes. Multiple moderator analyses were conducted to explore possible explanations for this heterogeneity.

9.4. Risk of bias analysis

Scores on each of the risk of bias items were summed to estimate a total risk of bias score. This continuous variable was then used to examine the relationship between effectiveness and risk of bias in meta‐regression models.

For perpetration outcomes, risk of bias was not associated with effect size under a random effects model of meta‐regression ( b  = 0.003; SE  = 0.006; z  = 0.50; p  = .621) or under the MVA model ( b  = 0.014; SE  = 0.014; z  = 1.01; p  = .156). Similarly, risk of bias scores did not significantly predict bullying victimization effect sizes under a random effects meta‐regression ( b  = 0.007; SE  = 0.005; z  = 1.30; p  = .195) or the MVA model ( b  = 0.012; SE  = 0.012; z  = 1.006; p  = .157).

9.5. Moderator analyses 8

9.5.1. evaluation method.

Our meta‐analysis further investigated the effectiveness of antibullying programs in relation to the methodological designs used by evaluation studies. The breakdown of results by methodological design is also shown in Tables  9 and  10 for bullying perpetration and victimization outcomes respectively.

Primary studies employing age cohort designs associated with the largest effect sizes for both bullying perpetration (OR = 1.474; 95% CI, 1.39–1.56; p  < .001) and bullying victimization (OR = 1.302; 95% CI, 1.230–1.378; p  < .001) under a random effects model. Similarly, AC studies were associated with the largest effect sizes under the MVA model also (perpetration OR = 1.422; 95% CI, 1.36–1.46; p  < .001) and victimization OR = 1.289; 95% CI, 1.29–1.35; p  < .001).

Under the MVA model of meta‐analysis, mean effect sizes were the same for RCT evaluations (OR = 1.171; 95% CI, 1.08–1.27; p  < .001) and BA/EC evaluations (OR = 1.170; 95% CI, 1.05–1.31; p  = .005) for bullying perpetration outcomes. Moreover, the differences between RCT evaluations (OR = 1.117; 95% CI, 1.03–1.22; p  = .01) and BA/EC evaluations (OR = 1.188; 95% CI, 1.07–1.33; p  = .002) were marginal for bullying victimization outcomes under the MVA model.

In relation to bullying victimization outcomes, before‐after/experimental‐control designs gave the second largest mean effect size (OR = 1.225; 95% CI, 1.085–1.383; p  = 0.001), followed by RCTs (OR = 1.210; 95% CI, 1.091–1.342; p  < .001) under a random effects model. However, the result was the opposite for bullying perpetration outcomes under a random effects model (RCT: OR = 1.244; 95% CI, 1.123–1.379; p  < .001; BA/EC: OR = 1.187; 95% CI, 1.044–1.350; p  = 0.009).

Due to the marginal differences and lack of clear pattern in which method was associated with the largest effect sizes (between RCT and BA/EC) further moderator analysis was not conducted.

9.5.2. Location of intervention

Mean effects for bullying perpetration and bullying victimization outcomes are presented graphically in Figures  5 and  6 , respectively. Table  11 outlines the mean effects for each of the 12 countries for both bullying perpetration and victimization outcomes under both the MVA model and the random effects model.

Forest plot of effect size by location: school‐bullying perpetration

Forest plot of effect sizes by location: school‐bullying victimization

Moderator analyses results: Location of evaluation

Evaluations conducted in Greece were associated with the largest effect sizes for bullying perpetration outcomes, followed by Norway, Italy, United States, and Finland under the MVA model of meta‐analysis. Evaluations conducted in Italy were associated with the largest mean effect sizes in relation to bullying victimization, followed by Spain, Norway, United States, and Finland under the MVA model of meta‐analysis. Additionally, evaluations conducted in Germany and the UK gave significant mean effects when computed using the MVA model.

Under the random effects model, Greek evaluations were similarly associated with the largest effect sizes for bullying perpetration, followed by Spanish and Norwegian evaluations. Evaluations conducted in Italy and the United States were also associated with significant mean effects for reductions in bullying perpetration. In relation to bullying victimization, evaluations conducted in Spain and Italy were associated with very similar mean effect sizes and were the largest of the 12 effect sizes, followed by evaluations conducted in Norway. Evaluations conducted in Australia were also associated with significant mean effects in reducing bullying victimization ( p  < .05) and evaluations conducted in Finland and the United States were nearly statistically significant ( p  = .05 and p  = .06, respectively) under the random effects model.

Due to the large number of different countries and the unequal number of studies in each location, further subgroup analyses were not conducted.

9.5.3. Publication type and year

Table  12 outlines the mean summary effect sizes for each of the publication type moderators for bullying perpetration and victimization outcomes. Evaluations for which data was received via email correspondence from evaluators gave the largest mean effect sizes for both bullying perpetration and bullying victimization. Differences in the mean effect sizes for evaluations reported via unpublished dissertations, either masters or doctoral theses, gave the smallest mean effect sizes for both bullying perpetration and victimization outcomes. Subgroup analysis was not conducted further using these categorizations due to the imbalance in numbers of evaluations in each category (i.e., evaluations were overwhelmingly published in peer‐reviewed journal article format).

Moderator analyses results: Publication type

However, additional analysis was conducted to examine any potential differences between peer reviewed and nonpeer reviewed evaluations. Therefore, the above categories were collapsed, and evaluations reported by dissertation, chapter, correspondence and governmental reports (perpetration n  = 23; victimization n  = 21) were compared to evaluations published via peer‐reviewed journal article.

Under the MVA model, non‐peer‐reviewed evaluations gave a larger (OR = 1.493; 95% CI, 1.266–1.761; p  < .001) mean effect size than peer‐reviewed evaluations (see Table  11 ). Moreover, moderator analysis indicated that the difference was statistically significant ( Q B  = 12.861; df  = 1; p  < .001). However, under the random effects model, both groups gave similar effect sizes for bullying perpetration outcomes, and the difference between peer‐reviewed (see Table  11 ) and non‐peer‐reviewed (OR = 1.309; 95% CI, 1.137–1.508; p  < .001) was not statistically significant ( Q B  = 0.595; df  = 1; p  = .441).

For bullying victimization outcomes, similar results were obtained. Under the MVA model, non‐peer‐reviewed evaluations gave statistically significant larger mean effect sizes (OR = 1.403; 95% CI, 1.262 1.560; p  < .001) than peer‐reviewed evaluations (see Table  11 ; Q B  = 27.197; df  = 1; p  < .001). Yet, there was a marginal difference under the random effects model between peer‐reviewed (see Table  11 ) and non‐peer‐reviewed (OR = 1.231; 95% CI, 1.059–1.431; p  = .007) and the difference was not statistically significant ( Q B  = 0.048; df  = 1; p  = .827).

The mean summary effect size for “2009” studies on the year of publication moderator was OR = 1.487 (95% CI, 1.430–1.546; p  < .001) under the MVA model and OR = 1.411 (95% CI, 1.315–1.513; p  < .001) under the random effects model for bullying perpetration outcomes. Across both computational models these summary effects were larger than those for studies labeled “2016” on bullying perpetration for the MVA model (OR = 1.243; 95% CI, 1.667–1.324; p  < .001) and the RE model (OR = 1.184; 95% CI, 1.087–1.289; p  < .001). Moderator analysis analogous to the ANOVA showed that this difference was statistically significant ( Q B  = 76.412; df  = 1; p  < .001) under fixed effects and mixed effects analysis ( Q B  = 9.676; df  = 1; p  = .002).

In relation to bullying victimization, the mean summary effect size for studies labeled “2009” was larger (OR = 1.322; 95% CI, 1.220–1.432; p  < .001) under the MVA model than the mean summary effect size for studies labeled “2016” (OR = 1.229; 95% CI, 1.175–1.285; p  < .001). Moderator analysis analogous to the ANOVA found that this difference was statistically significant ( Q B  = 10.115; df  = 1; p  = .001) but the difference between odds ratios was marginal. However, under the random effects model the minimal difference between the “2009” studies (OR = 1.215; 95% CI, 1.094–1.350; p  < .001) was not statistically different to the mean summary effect size for “2019” studies (OR = 1.223; 95% CI, 1.139–1.313; p  < .001; Q B  = 0.010; df  = 1; p  = .920).

9.5.4. Intervention program

The mean summary effect sizes for 10 different intervention programs in relation to reducing bullying perpetration behaviors and 9 different intervention programs in relation to reducing bullying victimization behaviors. Table  13 outlines the effectiveness of specific antibullying programs in reducing both school‐bullying perpetration and victimization. The effectiveness of these programs varied greatly.

Moderator analyses results: Intervention program

In relation to school‐bullying perpetration outcomes, the OBPP was associated with the largest mean effect sizes. In addition, evaluations of the OBPP in Norway were associated with larger summary effect sizes than evaluations of OBPP conducted in the United States. However, the difference was not statistically significant for school‐bullying perpetration outcomes when moderator analysis analogous to the ANOVA was conducted ( Q b  = 3.65; df  = 1; p  = 0.06).

Other programs were significantly effective in reducing school‐bullying perpetration behaviors, for example KiVa, Second Step, and Steps to Respect. Positive effect sizes (i.e., OR > 1) were also observed for the BPYS and NoTrap! programs but these effects were not statistically significant in relation to reduction in bullying perpetration outcomes. Negative effects were found for two antibullying programs, the fairplayer manual and ViSC, although these effects were not statistically significant.

In relation to school‐bullying victimization outcomes, NoTrap! was associated with the largest mean effect size, followed by the BPYS Program, and then the OBPP. Our analysis identified that other antibullying programs were also significantly effective in reducing school‐bullying victimization, for example, Steps to Respect and KiVa.

Again, effect sizes for the OBPP varied between evaluations conducted in Norway and evaluations conducted in the United States for bullying victimization outcomes. Moreover, our analysis found that the difference in the magnitude of these effect sizes was statistically significant ( Q b   =  74.95; df  = 1; p  < 0.001). Our analysis also identified negative effects of the Second Step program in relation to bullying victimization outcomes. Evaluations of the ViSC program also had a negative effect on bullying victimization, although this effect was not statistically significant.

9.5.5. Unit of allocation/randomization

Table  14 outlines the mean effects for subgroups of studies according to how participants were allocated to experimental or control groups. Results are presented for bullying perpetration and victimization outcomes for all studies that allocated studies in classes, schools, or individual students. The mean effects for RCT and BAEC for each allocation unit are also presented separately.

Moderator analyses results: Unit of allocation/randomization

In relation to bullying perpetration outcomes, under the MVA model, studies that assigned participants in classes were associated with the largest effect sizes. However, the difference between the mean effect for all evaluations that used classes or schools as the unit of allocation were verging on statistically significance ( Q b   =  3.705, df  = 1, p  = .054). Under the random effects model, evaluations that assigned students to experimental conditions were associated with the largest effect size for bullying perpetration outcomes when all designs were included, and for RCT evaluations and BA/EC evaluations individually. However, the mean effect size for many of the subgroups were not collectively statistically significant overall under the random effects model.

Similarly, under the MVA model, evaluations conducted using a RCT design, and assigned classes to conditions, were associated with the largest effect size for bullying perpetration, although the mean group for this subgroup was not statistically significant. Moreover, moderator analysis analogous to the ANOVA found that the difference in the mean effect size for RCT designs that assigned classes to experimental and control conditions were not statistically different to RCT designs that assigned schools to experimental and control conditions ( Q b   =  1.140, df  = 1, p  = .286 ) .

In relation to BAEC designs, evaluations that assigned students to experimental conditions were associated with the largest mean effect size, although the effect was not statistically significant. However, the difference between the mean effect for BAEC evaluations that assigned classes and those that assigned schools to conditions was statistically significant under the MVA model ( Q b   =  4.551, df  = 1, p  = .033).

For bullying victimization outcomes, studies where the unit of allocation was classes of participants were associated with the largest effect sizes, followed by schools and individual students under the MVA model. The difference between studies that allocated classes and studies that allocated schools was statistically significant ( Q b   =  12.450, df  = 1, p  < .001). This pattern was observed when all designs were included, and for the subgroup of RCT evaluations and the subgroup of BA/EC evaluations. Thus, when participants were assigned in classes the mean effect size for these RCT evaluations were significantly associated with larger effect sizes ( Q b   =  13.590, df  = 1, p  < .001) for reductions in bullying victimization than RCT evaluations that assigned schools. Yet the difference between the mean effect sizes for BA/EC evaluations that assigned classes were not statistically significant ( Q b   =  3.359, df  = 1, p  = .067) than BA/EC evaluations that assigned schools to experimental conditions.

9.5.6. Conflict of interest

COI was a categorical moderator variable with three levels: high‐risk (H), low‐risk (L), and possible‐risk (P). Moderator analysis analogous to the ANOVA was conducted so as to assess the differences between evaluations on each level. Studies categorized as possible‐risk on COI variable were excluded from subgroup comparisons to establish the differences between evaluations that were clearly high‐risk and evaluations that were clearly low‐risk. Table  15 outlines the mean summary effects for each group for both bullying perpetration and bullying victimization outcomes.

Moderator analyses results: Conflict of interest

Note : Four studies and six studies were excluded from the present moderator analysis for perpetration and victimization outcome respectively as not enough information was available.

Moderator analyses found that the difference between high‐risk and low‐risk studies on COI variable was statistically significant for bullying perpetration outcomes under both the MVA model ( Q B  = 50.129; df  = 1; p  < .001) and the random effects model ( Q B  = 4.900; df  = 1; p  = .027). This suggests that evaluations considered to have high COI were associated with larger overall effect sizes for bullying perpetration. Similarly, high‐risk COI studies were significantly associated with slightly larger effect sizes for bullying victimization in comparison to low‐risk COI studies when compared under both the MVA model ( Q B  = 16.127; df  = 1; p  < .001) and the random effects model ( Q B  = 4.449; df  = 1; p  = .035).

9.5.7. Program specificity

The majority of evaluations included in our meta‐analysis were of highly specific intervention programs, that is, those that targeted bullying behaviors and no other outcomes. Consistently across computational model and both perpetration and victimization outcomes these subgroups were associated with the largest mean effect sizes. These results are presented in Table  16 . Additionally, highly specific programs were the only subgroup of evaluations that gave a statistically significant mean summary effect under both the MVA model and the random effects model for bullying victimization outcomes. In relation to bullying perpetration outcomes, the subgroup of evaluations that were coded as “medium” on the program specificity moderator were associated with a statistically significant mean effect size under the MVA model ( p  < .001) and the random effects model ( p  = .036).

Moderator analyses results: Program specificity

10. DISCUSSION

10.1. summary of main findings.

Overall, our updated meta‐analysis found that school‐based antibullying programs are effective in reducing both school‐bullying perpetration and victimization. For school‐bullying perpetration the weighted mean OR = 1.324 under the MVA model, or OR = 1.309 under a random‐effects model (RE) were associated with reductions of approximately 19–20%. 9 In comparison, the weighted mean ORs for bullying victimization outcomes were 1.248 and 1.242 under the MVA model and the random effects model respectively. These mean effect sizes correspond to an approximate reduction in bullying victimization of 15–16%. These results suggest that the included interventions were slightly more effective at reducing school‐bullying perpetration than school‐bullying victimization.

The results of this meta‐analysis are consistent with findings from most of previous reviews that indicate that antibullying programs have a small but significant effect, with some variations in overall results being attributable to methodological differences in inclusion and exclusion criteria (Ttofi et al.,  2014 ). Our mean effect sizes are also consistent with the earlier review (Farrington & Ttofi, 2009 ; Ttofi & Farrington,  2011 ), although the differences further outline that moderator variables such as methodological design may be responsible for variability. For example, the weighted mean effect sizes for both bullying perpetration and bullying victimization outcomes estimated in the earlier Campbell report were larger than those estimated in the present report.

Yet, we included publication year as a categorical moderator variable in the present analysis. We found that more recent studies (i.e., those that were not included by Farrington & Ttofi,  2009 ) were significantly different to studies that were included in the earlier review. Namely, recent studies were actually associated with significantly larger effect sizes for both bullying perpetration and victimization outcomes (see Section 8.5.3).

Therefore, as we excluded studies considered to have utilized less scientifically rigorous methodological designs this may explain the differences in the weighted mean effect sizes. Specifically, we excluded evaluations conducted using “other experimental‐control designs,” described in the earlier review as evaluations in which participants were assigned to experimental and control conditions but bullying outcomes were only measured after implementation of the intervention. Thus, attributing any change in behaviors to the intervention is potentially risky because there may be other reasons why a positive effect of the intervention was observed. For example, the experimental and control groups were not comparable at baseline, but this remains unknown as no measure of bullying was obtained.

Thus, the inclusion of these less methodologically rigorous evaluations may explain why the weighted mean effects sizes reported in the earlier review were larger than those reported in the current report, but our moderator analysis found a contradictory pattern. The following sections of this report will aim to discuss the findings obtained by our moderator analyses and also the strengths and limitations of the current analysis and potential avenues for future research. The heterogeneity in this meta‐analysis was very large for both bullying perpetration and victimization outcomes. This may suggest that there was a wide range of effects across programs and we may not be able to explain differences using moderator analysis.

10.2. Moderator analyses

10.2.1. evaluation method.

Under both the MVA and random effects models, evaluations conducted using age cohort designs were identified to be, collectively, the most effective, or at least associated with the largest mean effect sizes. This is consistent with Farrington and Ttofi's ( 2009 ) review. This methodological design was first introduced as an evaluation design for the OBPP (Olweus,  1991 ). This approach has been criticized for the potential threats to internal validity, history and testing effects (Farrington & Ttofi,  2009 , p. 15). It has been suggested that this design avoids the threats of aging and maturation effects, as individuals within the same school act as a control group for same‐aged experimental participants (Olweus,  2005a ). However, this design is vulnerable to cross‐contamination between experimental and control participants which would impact the overall effectiveness. Notably, intervention researchers have tested the OBPP with other methodological designs (e.g., Bauer et al.,  2007 ) which resulted in smaller effects.

Interestingly, the pattern between RCTs and BA/EC designs was less clear. In relation to bullying victimization outcomes, evaluations using BA/EC designs appear to be more effective than evaluations using RCT designs. However, for bullying perpetration outcomes, evaluations using RCT designs appear to be more effective than evaluations that utilized BA/EC designs. Further research is needed to understand these effects. However, the nature of these analyses is correlational and the differences between effect sizes are marginal. Thus, no concrete conclusion can be drawn in relation to the association between randomized and nonrandomized quasi experimental designs and effect size in the present context.

10.2.2. Unit of allocation/randomization

In theory, RCTs are the best method of evaluation of interventions because random allocation ensures that any observed differences between experimental and control groups occurs as a result of experimental manipulation, thus giving the best possible internal validity (Farrington,  1983 ,  2003 ). However, the unit of random allocation can have an impact on internal validity. For example, we assume that individuals are randomly assigned to experimental and control conditions, so that RCT designs adequately account for the random variation that occurs in real‐world research (Weisburd,  2003 ).

However, in practice, evaluations of antibullying programs may be more likely to assign groups of individuals, for example in terms of classrooms or schools, to experimental conditions rather than individual students. This is true for both randomized (e.g., classrooms, Chaux et al.,  2016 ; or schools, Espelage et al.,  2015 ) and nonrandomized (e.g., classrooms, Ortega‐Ruiz et al.,  2012 ; or schools, Rawana et al.,  2011 ) methodologies. When this is the case, we need larger numbers to ensure adequate statistical conclusion validity and avoid issues of selection effects and differential attrition (Farrington & Ttofi,  2009 ; Ttofi & Farrington,  2011 ). There was a lot of variation in the unit of allocation in our primary studies, which may explain why we did not find that one methodological design was more effective than another.

Moreover, the majority of included evaluations did not use the same unit for allocation and analysis, thus, posing a threat to our results. We approach the results therefore with caution, favouring more conservative estimates. Furthermore, the relationship between the unit of randomization/allocation moderator variable and the effect sizes for bullying perpetration and victimization outcomes was unclear. Whether or not the differences between subgroups of evaluations that assigned classes or schools to experimental conditions were statistically significant or not depended on the computational model used and the bullying outcome in question. For bullying perpetration, the differences between studies based on unit of allocation were not statistically significant for randomized and nonrandomized studies. For bullying victimization outcomes, studies where classes were the unit of allocation were associated with the largest effect sizes when all designs where included and for randomized evaluations, but not for nonrandomized evaluations, separately.

Risk of bias analysis also found that a large number of RCT studies were categorized as being high risk for allocation‐related items on the EPOC tool. Therefore, the differences observed between primary evaluations in our meta‐analysis may be due to the observation that largely the unit of allocation and the unit of analysis were not the same in primary studies. However, further analysis and investigation is needed to better understand these results.

10.2.3. Location of intervention

Overall, the results of our meta‐analysis are consistent with previous findings and show that school‐based antibullying programs have a modest but significant effect in reducing bullying behaviors. However, our meta‐analysis included evaluations of antibullying programs from a wide range of countries and specific intervention programs, far more than previous meta‐analyses (e.g., Cantone et al.,  2015 ; Chalamandaris & Piette,  2015 ; Evans et al.,  2014 ; Jiménez‐Barbero et al.,  2012 ,  2016 ). As a result, the results of this meta‐analysis are robust and have implications for bullying research globally.

Our analysis identifies that antibullying programs worldwide are effective in reducing school‐bullying perpetration and victimization by significant amounts. Moreover, evaluations in different countries appear to vary in effectiveness. In Greece, where evaluations included in our meta‐analysis were associated with the largest effect sizes, school‐bullying perpetration behaviors were reduced by approximately 40%. Evaluations conducted in the Norway, Italy and the United States were also effective in reducing bullying perpetration by approximately 21–25%.

Antibullying programs implemented and evaluated in Italy were associated with the largest reduction in school‐bullying victimization in our meta‐analysis, with the odds ratio effect size corresponding to an approximate reduction of 31%. Moreover, evaluations conducted in Spain and Norway reduced school‐bullying victimization by approximately 28% and 23%, respectively. Evaluations conducted in Finland, Germany and the UK were also significantly effective, although less so, reducing school‐bullying victimization by approximately 8–12%.

There are many potential explanations for the differences in effectiveness observed between countries. For example, definitions of school‐bullying, and behaviors that constitute bullying, differ between countries. Previous research conducted by Smith et al. (2000) showed that school‐bullying is perceived differently across different countries and cultures and this may explain variability in bullying reporting. Definitions of school bullying, and behaviors that constitute bullying, differ between countries. For example, Smith et al. ( 2016 ) showed that school bullying in Eastern cultures manifests more often as exclusion or isolation of an individual victim. In comparison, school bullying in Western cultures comprises a wider range of physical, verbal and relational forms of aggression.

Our meta‐analysis included several examples of cases where the same intervention program was evaluated in different countries (e.g., KiVa program in Finland (Kärnä et al.,  2013 ) and in Italy (Nocentini & Menesini, 2016)). While societal practices, educational systems, and individual lifestyles may differ greatly, some argue that there may be some support for the cross‐national applicability of specific intervention programs. However, there is a current lack of existing research comparing the effectiveness of specific interventions in specific countries.

Previous research has indicated that are also cultural differences in bullying behaviors among adolescents (e.g., Smith et al.,  2016 ). As such, an antibullying program to reduce these behaviors may be impacted by these differences. This is particularly evident when we observe the variations in effect sizes for the OBPP (Olweus,  1993 ) and the KiVa antibullying program. These programs may be the most well‐known antibullying programs that are commercially available, and as such as the only examples in our review of interventions evaluated in completely different locations.

The OBPP program was originally designed and implemented in Norway, and it is therefore not surprising that the OBPP program appears to be effective in reducing both school‐bullying perpetration and victimization when evaluated in Norway, compared to evaluations in the United States (see Table  13 ). While the program was still significantly effective in the United States, the percentage decrease in school‐bullying perpetration was roughly 25% and in school‐bullying victimization was roughly 11%. These figures are lesser in comparison to the decreases in bullying behaviors seen in Norwegian evaluations (35% perpetration; 29% victimization). These differences could be attributed to different evaluation methodologies (see Gaffney et al., 2019), however, they most likely reflect cultural and societal differences between youth in Norway and youth in the United States.

Interestingly, the opposite is observed with the KiVa program. When KiVa was evaluated in Finnish samples, the program was effective in reducing school‐bullying perpetration by approximately 4–5% and school‐bullying victimization by approximately 6% (Kärnä et al.,  2011a ,  2011b ,  2013 ). However, when evaluated in Italian primary and secondary schools, the effect sizes were much larger. Nocentini and Mensini (2016) found that KiVa was effective in reducing school‐bullying perpetration by approximately 15–20% and school‐bullying victimization by approximately 25%.

In the case of KiVa, each of the evaluations used the same methodology (i.e., RCT), but varied greatly in the sample size. Thus, further research is needed to explain why some interventions (e.g., OBPP or KiVa) appear to be more effective in some samples compared to others. The programs are still effective, but the variation in effect size could be attributable to a number of different methodological and implementation factors that warrant further exploration.

10.2.4. Intervention program

Following this logic, we also explored the effectiveness of the specific antibullying programs. Out of the four most widely disseminated antibullying programs included in our review (i.e., KiVA, NoTrap!, OBPP, ViSC), the OBPP was collectively the most effective in reducing school bullying perpetration of these. Across 11 evaluations, the OBPP reduced bullying perpetration by approximately 26%, which was larger than any other widely disseminated program.

In relation to school‐bullying victimization outcomes, the NoTrap! program was the most effective, reducing victimization by around 37%. NoTrap! also reduced bullying perpetration by a considerable amount, approximately 22%, but this effect was not statistically significant. The KiVA program, significantly reduced school bullying perpetration by approximately 9% and school bullying victimization by approximately 11%. The ViSC program was the only program to increase bullying perpetration (by roughly 4%) and bullying victimization (by roughly 4%) although these effects were not statistically significant.

Another moderator we used to code differences between included evaluations was the specificity of the intervention program. In other words, we evaluated each intervention program on how specific it related to bullying behaviors. Unsurprisingly, our findings suggest that antibullying programs gave the largest overall effect sizes. While the significance of the differences between subgroups was not computed due to the large discrepancies between the numbers of evaluations included in each subgroup.

However, our inclusion criteria for the current report was strictly concerned with school‐bullying intervention programs and behavioral outcomes of bullying. As such, we may have overlooked effective programs that only included nonbehavioral outcomes of bullying (e.g., attitudes toward bullying, awareness of bullying) or other problem behaviors (e.g., peer aggression or victimization, mental health issues, juvenile delinquency, etc.) that occur among young people in schools. Changes in these behaviors may also impact bullying, either directly or indirectly, yet, more research is needed to understand this potential effect. Most obvious in the present report is how programs that target specifically school‐bullying may impact cyber‐bullying, and vice versa, given the significant overlap in the prevalence of these behaviors (Baldry et al.,  2017 ).

Further research is also needed to better understand specifically “what works” in these “specific interventions.” In the previous review, (Farrington and Ttofi  2009 ; Ttofi & Farrington,  2011 ) conducted detailed coding of interventions and evaluations and analyzed how effect sizes varied between components and features of primary studies. For example, parent training, playground supervision, and more intense and longer programs were significantly correlated with larger reductions in bullying perpetration (Ttofi & Farrington,  2011 ). Moreover, several intervention components were associated with larger reductions in bullying victimization (e.g., videos, disciplinary methods, co‐operative group work and more intense and longer programs). Therefore, an important avenue for future research is to assess the differences in effectiveness of antibullying programs according to specific intervention components across the 100 evaluations included in our meta‐analysis. Such research would have important implications for policy and the development of future antibullying programs.

Additionally, it appears that since 2009 several large‐scale antibullying programs have been implemented and evaluated (e.g., KiVa; Kärnä et al.,  2013 ; NoTrap!; Menesini et al.,  2012 ; Palladino et al.,  2016 ). Because there is typically more information available on the specific components of these programs, we may be able to code more specific details in future analyses. For example, many studies may fit the criteria for “parent training,” but there is a significant difference between the intensity of parental involvement. For example, some studies may include parents merely by sending letters home with participant children (e.g., Brown et al.,  2011 ), while others include parents more actively by holding information evenings or requiring children to complete take‐home tasks with parental involvement (e.g., Berry & Hunt,  2009 ; Domino,  2013 ).

Earlier research highlighted how varying levels of implementation of each intervention component may explain variability in intervention outcomes (Bloom et al.,  2003 ). Interestingly, a narrative review by Smith et al. ( 2003 ) reported that although 14 whole‐school antibullying programs obtained modest effects overall, those that monitored implementation obtained twice the mean effects on self‐reported rates of bullying and victimization than those that did not monitor implementation. Thus, additional analyses are required to better understand specifically what works in existing antibullying programs and the underlying mechanisms of behavioral change

10.2.5. COI and publication type

Possibly the most conclusive results from our moderator analyses were observed in relation to COI and publication type. First, across both computational models and outcomes, studies that were categorized as being high‐risk for COI were associated with significantly larger reductions in bullying perpetration and victimization. Second, under the MVA model of meta‐analysis, non‐peer‐reviewed evaluations were associated with significantly larger reductions in both bullying perpetration and victimization outcomes. However, the same results were not observed under the random effects.

We examined COI in terms of the involvement of the program developer in the evaluation. Our results may indicate possible sources of biases. For example, it may be that when the individual, or team, that are credited with developing an antibullying program are also involved in the evaluation of said intervention, biases such as confirmation bias may impact the results. However, it may not be a perceivably “negative” source of bias. Perhaps, when the program developer is involved in the implementation of the program, the intervention is simply delivered better and more effectively. There are a number of other factors that could also be affected and in turn impact the effect size, such as teacher and staff efficacy and motivation to participate the in the program.

There are more sophisticated measures of COI (e.g., Eisner et al.,  2012 ) that include elements such as whether or not the evaluator could potentially benefit financially from the intervention program. Further indicators of COI are thus needed to better understand the impact on evaluation results. For example, our findings in relation to COI and larger effect sizes may be explained as: evaluations in which the program developer was included appear to be more effective because of the expertise and intricate knowledge of the developer. Therefore, the results may reflect differences in the quality of program implementation rather than troublesome biases. Additional research is needed.

10.3. Limitations and avenues for future research

Like most meta‐analyses, the current report is largely limited by the lack of understanding as to what is the “true effect.” When comparing mean effect sizes between moderators for example, it is difficult to determine the validity of the result. Throughout our discussion of result we discuss that one subgroup of studies was associated with larger or smaller effect sizes than another, and the statistical significance of these differences. Thus, we avoid saying studies in subgroup A (e.g., evaluations conducted in Greece) are more effective than studies in subgroup B (e.g., evaluations conducted in Italy). Due to the correlational nature of our moderator analyses we cannot make causal inferences. In addition to this limitation, and those previously discussed (Section  9.2 ), the following section of this report discusses some further limitations.

10.3.1. Measurement of bullying

Experts in the area of school‐bullying research have outlined how there still remain issues of comparability in the assessment of school‐bullying perpetration and victimization (Volk et al.,  2017 ). Studies included in the present meta‐analysis used a wide variety of quantitative measures of school‐bullying behaviors, including self‐report measures (e.g., the Revised Olweus Bully/Victim Questionnaire—Olweus,  1986 ,  1996 ), or peer‐report measures (e.g., the Participant Role Questionnaire—Salmivalli et al.,  1996 ). One issue that arises is that the timeframe within which participants are required to indicate the frequency of bullying can vary greatly. One scale may ask about bullying experiences within the last 3 months, while another may ask about ever having experienced, or participated in, school‐bullying. Moreover, included studies utilized a mixture of continuous or dichotomous measures of school‐bullying, and the cut‐off points used to categorize someone as either a bully, victim, or not‐involved also varied.

Furthermore, the majority of evaluations included in our analysis reported bullying outcomes at different time points, largely, before implementation, after implementation, with a possible additional follow‐up time point. However, we computed effect sizes using measures of bullying taken before implementation and immediately post implementation of the intervention. Therefore, we cannot generalize results to the long‐term effectiveness of antibullying programs, or any potential influence of dose‐response effect. Future research should aim to examine the longitudinal effectiveness of interventions to reduce bullying perpetration and victimization in the long‐term.

When conducting our systematic searches for the present review, we did not set restrictions based on measurement issues, other than including quantitative measures of school‐bullying behaviors. However, types of reports, for example, could influence the overall effectiveness effect size. This may possibly explain why our meta‐analysis found that programs are more effective in reducing bullying perpetration outcomes. For example, if programs are concerned with raising awareness about bullying and the associated negative impact on victims, participants who reported bullying perpetration before the intervention may be less likely to self‐report bullying behaviors after completing the program. As a result, the intervention may be perceived as being effective, but the change in reports of bullying may have been a result of social desirability responding (He et al.,  2015 ; Rigby & Johnson,  2006 ). Conversely, raising awareness on the negative impact of school bullying may lead to increased reporting of victimization due to sensitization effects (Stevens et al.,  2000 ). Notably, sensitization effects due to raised awareness may affect not only self‐report data but also peer nomination data and teacher reports (Smith et al.,  2003 , p. 597). Therefore, future research could aim to examine whether the style of report used, differing cut‐off points and varying timeframes affect estimations of intervention effectiveness.

10.3.2. Cyberbullying behaviors

Another key limitation of the present review is the omission of cyberbullying behaviors. Prominent researchers in the area have argued that cyberbullying behaviors do not warrant a completely separate line of study, because of the significant overlap between offline and online bullying (Olweus & Limber,  2017 ). A recent meta‐analysis of cyberbullying intervention and prevention programs found that, out of studies assessing various facets of cyberbullying, a large number were concerned with this overlap (Gaffney et al., 2019). The Gaffney et al. (2019) meta‐analysis concluded that anticyberbullying programs were effective in reducing cyberbullying perpetration by roughly 9–15% and cyberbullying victimization by roughly 14–15%. As illustrated in that other review, there is a need for future research to assess the effectiveness of intervention programs that target both online and offline bullying concurrently. As a result of the significant overlap (e.g., Waasdorp & Bradshaw, 2015), it is important for policy makers, researchers, and program developers to know whether or not these forms of aggressive behaviors should be targeted together or individually. Future research should aim to examine the effectiveness of programs designed to reduce school‐bullying on cyberbullying outcomes, and vice versa. Additional analysis to examine the differences between programs that target offline and online behaviors concurrently in terms of effectiveness to reduce both school‐ and cyber‐bullying is also needed.

10.3.3. Models of meta‐analyses

The current report presents findings using two computational models of meta‐analyses: the random effects model and the multiplicative variance adjustment model. While, the random effects model is often suggested as the preferred model for meta‐analyses in social sciences, for reasons already discussed (Section  7.3 ), this approach is also limited. However, even though many meta‐analyses in medical sciences (e.g., Ayieko et al.,  2014 ; Dorjee et al.,  2018 ; Woolf‐King et al.,  2013 ) have used the MVA model as an alternative method of accounting for between‐study heterogeneity in weighted mean effect sizes, this model is yet to be widely accepted in behavioral sciences. A number of recent publications (e.g., Portnoy & Farrington,  2015 ; Zych et al.,  2019 ) have begun to use the MVA model.

It is evident in the current report that the results are influenced by the computational model used. The overall mean effect sizes for bullying perpetration and victimization were not that different under both models but the results of moderator analyses were greatly influenced by how we accounted for the between‐study heterogeneity. Further research is needed in order to examine the reasons for this and also evaluate how best to choose an appropriate computational model when conducting a meta‐analysis.

10.4. Concluding remarks

This report presents an updated systematic and meta‐analytical review of the effectiveness of school‐bullying intervention and prevention programs. Overall, our review found that school‐based antibullying programs are effective in reducing both bullying perpetration and bullying victimization, and that effect sizes can vary according to several moderator variables. However, further research is needed to better understand the reasons for variation in observed effect sizes. Research is needed to investigate the specific components of antibullying programs that work best to reduce bullying behaviors. The results of our meta‐analysis have important implications for policy and the development of future antibullying programs, but future research should aim to better understand the effective mechanisms in bullying intervention and prevention.

11. TECHNICAL APPENDICES

11.1. calculating the before‐after intervention effect.

Williams et al. ( 2015 ) evaluated the effectiveness of the Start Strong program based on students' self‐reported experiences of bullying victimization. The primary study found that, at baseline, 23% of participants in the experimental group ( N  = 717) reported bullying victimization, while 23% of participants in the control group ( N  = 800) also reported bullying victimization at baseline. Hence, the baseline OR was calculated as follows (Table  17 ):

Data used to estimate baseline odds ratio

Thus, the OR before  = 0.999, Ln OR before  = −0.002, and var Ln OR before  = 0.015. Williams et al. ( 2015 ) report that after implementation of the Start Strong program, bullying victimization was reported by 28% of experimental participants and 34% of control participants. Accordingly, the posttest OR was calculated as follows (Table  18 ):

Data used to estimate postintervention odds ratio

Thus, the OR after  = 1.323; Ln OR after  = 0.28; and var Ln OR after  = 0.013. Employing these figures, the ln OR for the intervention effect of the Start Strong program was calculated as:

The ln OR change is computed as the difference between the before and after effect size and the variance of this new estimate is adjusted by multiplying the sum of the variances of before and after variances by 0.75. This is an approximation of the assumed correlation between before and after effect sizes. The ln OR change and the SE of ln OR change were then entered into CMA as an estimation of the intervention effect.

11.2. Multiplicative variance adjustment

In the present meta‐analysis, the summary effect size estimated for bullying perpetration was OR = 1.324 with 95% confidence intervals of 1.298–1.351 under a fixed effects model. The effect size in the MVA model is the same as the effect size in the fixed effects model. The variance of the effect size in the MVA model is calculated as follows:

Therefore, in the above example of the summary effect size for bullying perpetration outcomes, the FE var is 0.000104. Therefore, with Q  = 458.555 and df  = 109, the MVA adjustment for fixed effects is 0.02098, calculated as:

Therefore, the adjusted standard error is 0.0209. In this example thus, the MVA fixed effect is OR = 1.324, and the 95% confidence intervals are 1.271–1.380.

11.3. Odds ratio to percentage conversion

The conversion from weighted mean odds ratio to percentage value is also described in the previous Campbell report (see Farrington & Ttofi, 2009 ). The formula involves assuming equal allocation of participants to experimental and control conditions and that the % of bullies and/or victims was lesser in the experimental condition than in the control condition (as supported by our overall positive mean effect size).

For example, if there are 200 participants in each experimental condition and approximately 30% of participants report bullying victimization in the control condition and 25% victims in the experimental condition, the numbers of victims and nonvictims would be as follows: (Table  19 ).

Data used to convert odds ratio to percentage

Therefore using the previously described formula for estimating an odds ratio, the following data would correspond to an odds ratio of 1.286 (i.e., [150 × 60]/[140 × 50]). Moreover, the percentage decrease would be approximately 16.67% (i.e., (10/60) × 100).

Using this basic formula, we can manipulate the % and number of victims in each experimental condition in order to achieve a odds ratio that corresponds to our weighted mean effect size (i.e., MVA: OR = 1.324 and RE: OR = 1.309 for bullying perpetration; MVA: OR = 1.248 and RE: OR = 1.242 for bullying victimization). Using the n values that give the closest possible mean effect size we can thus estimate the corresponding percentage reduction in either bullying perpetration or victimization outcomes.

APPENDIX A. 

Appendix: full search syntax, database: web of science.

Bully* AND Intervention AND Evaluation

Anti‐Bullying AND School AND Program* AND Evaluation

Anti‐Bully* AND Program* AND Outcome

Bully‐victim AND Prevention AND Evaluation

Bully* AND School AND Intervention

Bully* AND School AND Prevention

Database: Scopus

Bully* AND School AND Program*

Bully* AND School AND Evaluation

Bully* AND School AND Intervention AND Evaluation

Bully* AND School AND Prevention AND Evaluation

Anti‐bullying AND Program* AND Evaluation

Database: National Criminal Justice Reference Service

Bully* AND Prevention AND Evaluation

Anti‐bullying AND Program* AND Effect*

Database: PsycINFO

Bully* AND Intervention AND Program* AND Evaluation

Bully* AND Prevention AND Program* AND Effect*

Database: Cochrane Controlled Trials Register

Bully* AND Intervention AND Program*

Bully* AND Prevention AND Program AND Evaluation

Database: British Education Index

Bully* AND Prevention AND Program* AND Evaluation

Bully* AND Intervention AND Program* AND Effect*

Database: Embase

Database: medline, database: eric & criminal justice abstracts.

www.scholar.google.co.uk

APPENDIX B. 

Appendix: risk of bias results for included studies.

Note : H, hig risk, score 3; L, low risk, score 0; U, unclear risk, score 2. Risk of bias score is estimated as sum of scores on individual risk of bias items.

Abbreviations: AC, Allocation concealment; AS, Allocation sequence; BC, Baseline Equivalence on Characteristics; BE, Baseline Equivalence of Outcome; BOA, Blind Outcome Assessment; CP, Contamination Protection; ID, Incomplete Data; SOR, Selected Outcome Reporting.

Gaffney, H., Ttofi, M. M., & Farrington, D. P. (2021). Effectiveness of school‐based programs to reduce bullying perpetration and victimization: An updated systematic review and meta‐analysis . Campbell Systematic Reviews , 17 , e1143. 10.1002/cl2.1143 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]

Systematic review

Plain language summary on the Campbell website

1 The authors regret that more detailed information concerning specific combinations of keywords and databases searched as per the Campbell MECCIR reporting standards. This information is held on restricted access computers and due to COVID‐19 pandemic, the closure of University buildings, this data could not be retrieved.

2 Web of Science Core Collection database.

3 Unfortunately detailed information about the datas of searches cannot be provided for this review, contrary to MECCIR R35.

4 We were unable to double code in this review. However, as some studies were included in the present review and an earlier review (Farrington & Ttofi,  2009 ), a proportion of the studies were double‐coded.

5 A worked example is provided in Technical Appendix 10.1.

6 Calculated as: total number of students/number of classrooms.

7 A worked example of this adjustment is provided in Technical Appendix 10.2.

8 Moderator analyses under the MVA model will be greatly affected by the presence of very large studies in the meta‐analysis. Unfortunately, we were not able to follow recommendations made by the methods editor to windsorize weights or conduct sensitivity analyses by removing these large studies. Due to the COVID‐19 pandemic the software to carry out these tests was not available to us. Thus, the reader should consider the impact of large studies when interepting the results of moderator analyses under the MVA model.

9 The procedure used to estimate approximate percentage values for weighted mean odds ratios is provided in Technical Appendix 10.3.

REFERENCES TO INCLUDED STUDIES

• Alsaker, F. D. (2004). Bernese program against victimization to kindergarten and elementary schools. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 289–306). Cambridge University Press. [ Google Scholar ]
• Alsaker, F. D., & Valkanover, S. (2001). Early diagnosis and prevention of victimization in kindergarten. In Juvonen J. & Graham S. (Eds.), Peer harassment in school (pp. 175–195). Guilford. [ Google Scholar ]
• Andreou, E., Didaskalou, E., & Vlachou, A. (2007). Evaluating the effectiveness of a curriculum‐based anti‐bullying intervention program in Greek primary schools . Educational Psychology , 27 , 693–711. [ Google Scholar ]
• Avşar, F., & Alkaya, S. A. (2017). The effectiveness of assertiveness training for school‐aged children on bullying and assertiveness level . Journal of Pediatric Nursing , 36 , 186–190. 10.1016/j.pedn.2017.06.020 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Baldry, A. C., & Farrington, D. P. (2004). Evaluation of an intervention program for the reduction of bullying and victimization in schools . Aggressive Behavior , 30 , 1–15. 10.1002/ab.20000 [ CrossRef ] [ Google Scholar ]
• Battey, G.J.L. (2009). Can bullies become buddies? Evaluation of and theoretical support for an experiential education bully prevention curriculum with seventh grade students (Doctoral dissertation). Available from ProQuest Dissertations and Theses (UMI No. 3348633).
• Bauer, N. S., Lozano, P., & Rivara, F. P. (2007). The effectiveness of the Olweus bullying prevention program in public middle schools: A controlled trial . Journal of Adolescent Health , 40 , 266–274. [ PubMed ] [ Google Scholar ]
• Beran, T., & Shapiro, B. (2005). Evaluation of an anti‐bullying program: Student reports of knowledge and confidence to manage bullying . Canadian Journal of Education , 28 ( 4 ), 700–717. [ Google Scholar ]
• Beran, T., Tutty, L., & Steinrath, G. (2004). An evaluation of a bullying prevention program for elementary schools . Canadian Journal of School Psychology , 19 ( 1/2 ), 99–116. [ Google Scholar ]
• Berry, K., & Hunt, C. J. (2009). Evaluation of an intervention program for anxious adolescent boys who are bullied at school . Journal of Adolescent Health , 45 , 376–382. 10.1016/j.jadohealth.2009.04.023 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Bonell, C., Fletcher, A., Fitzgerald‐Yau, N., Hale, D., Allen, E., Elbourne, D., Jones, R., Bond, L., Wiggins, M., Miners, A., Legood, R., Scott, S., Christie, D., & Viner, R. (2015). Initiating change locally in bullying and aggression through the school environment (INCLUSIVE): A pilot randomised controlled trial . Health Technology Assessment , 19 ( 53 ), 1–110. 10.3310/hta19530 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Boulton, M. J., & Flemington, I. (1996). The effects of a short video intervention on secondary school pupils' involvement in definitions of and attitudes towards bullying . School Psychology International , 17 , 331–345. [ Google Scholar ]
• Brown, E. C., Low, S., Smith, B. H., & Haggerty, K. P. (2011). Outcomes from a school‐randomized controlled trial of Steps to Respect: A bullying prevention program . School Psychology Review , 40 ( 3 ), 423–443. 10.1037/e734362011-045 [ CrossRef ] [ Google Scholar ]
• Bull, H. D., Schultze, M., & Scheithauer, H. (2009). School‐based prevention of bullying and relational aggression: The fairplayer.manual . European Journal of Developmental Science , 3 ( 3 ), 312–317. [ Google Scholar ]
• Busch, V., De Leeuw, R. J. J., & Schrijvers, A. J. P. (2013). Results of a multibehavioral health‐promoting school pilot intervention in a Dutch secondary school . Journal of Adolescent Health , 52 ( 4 ), 400–406. 10.1016/j.adohealth.2012.07.008 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Chaux, E., Velásquez, A. M., Schultze‐Krumbholz, A., & Scheithauer, H. (2016). Effects of the cyberbullying prevention program Media Heroes ( Medienhelden ) on traditional bullying . Aggressive Behavior , 42 ( 2 ), 157–165. 10.1002/ab.21637 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Cissner, A. B., & Ayoub, L. H. (2014). Building healthy teen relationships: An evaluation of the Fourth R curriculum with middle school students in the Bronx . U.S.A: Center for Court Innovation. [ Google Scholar ]
• Ciucci, E., & Smorti, A. (1998). Il fenomeno delle pretonenze nella scuola: Problemi e prospettive di intervention [The phenomenon of bullying in school: Problems and prospects for intervention] . Psichiatria dell'infanzia e dell'adolescenza , 65 , 147–157. [ Google Scholar ]
• Connolly, J., Josephson, W., Schnoll, J., Simkins‐Strong, E., Pepler, D., MacPherson, A., Weiser, J., Moran, M., & Jiang, D. (2015). Evaluation of a youth‐led program for preventing bullying, sexual harassment, and dating aggression in middle schools . Journal of Early Adolescence , 35 ( 3 ), 403–434. 10.1177/0272431614535090 [ CrossRef ] [ Google Scholar ]
• Cross, D., Hall, M., Hamilton, G., Pintabona, Y., & Erceg, E. (2004). Australia: The friendly schools project. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 187–210). Cambridge University Press. 10.1017/CB09780511584466.011 [ CrossRef ] [ Google Scholar ]
• Cross, D., Monks, H., Hall, M., Shaw, T., Pintabona, Y., Erceg, E., Hamilton, G., Roberts, C., Waters, S., & Lester, L. (2011). Three‐year results of the Friendly School whole‐of‐school intervention on children's bullying behaviour . British Educational Research Journal , 37 ( 1 ), 105–129. 10.1080/01411920903420024 [ CrossRef ] [ Google Scholar ]
• DeRosier, M. E. (2004). Building relationships and combating bullying: Effectiveness of a school‐based social skills group intervention . Journal of Clinical Child & Adolescent Psychology , 33 ( 1 ), 196–201. 10.1207/S15374424JCCP3301_18 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• DeRosier, M. E., & Marcus, S. R. (2005). Building friendships and combating bullying: Effectiveness of S.S. GRIN at one‐year follow‐up . Journal of Clinical Child & Adolescent Psychology , 34 ( 1 ), 140–150. 10.1207/s15374424jccp3401_13 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Domino, M. (2011). The impact of Take the LEAD on school bullying among middle school youth (Doctoral Dissertation). Available from ProQuest Dissertation and Theses database (UMI No. 3434870).
• Domino, M. (2013). Measuring the impact of an alternative approach to school bullying . Journal of School Health , 83 ( 6 ), 430–437. 10.1111/josh.12047 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Elledge, L. C., Cavell, T. A., Ogle, N. T., & Newgent, R. A. (2010). School‐based mentoring as selective prevention for bullied children: A preliminary test . Journal of Primary Prevention , 31 , 171–187. 10.1007/s10935-010-0215-7 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Ertesvag, S. K., & Vaaland, G. S. (2007). Prevention and reduction of behavioural problems in school: An evaluation of the Respect program . Educational Psychology , 27 , 713–736. [ Google Scholar ]
• Espelage, D. L., Low, S., Polanin, J. R., & Brown, E. C. (2013). The impact of a middle school program to reduce aggression, victimization, and sexual violence . Journal of Adolescent Health , 53 ( 2 ), 180–186. 10.1016/j.jadohealth.2013.02.021 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Espelage, D. L., Low, S., Polanin, J. R., & Brown, E. C. (2015). Clinical trial of Second Step© middle‐school program: Impact on aggression & victimization . Journal of Applied Developmental Psychology , 37 , 52–63. 10.1016/j.appdev.2014.11.007 [ CrossRef ] [ Google Scholar ]
• Evers, K. E., Poskiparta, J. O., van Marter, D. F., Johnson, J. L., & Prochaska, J. M. (2007). Transtheoretical‐based bullying prevention effectiveness trials in middle schools and high schools . Educational Research , 49 , 397–414. [ Google Scholar ]
• Farmer, V. L., Williams, S. M., Mann, J. I., Schofield, G., McPhee, J. C., & Taylor, R. W. (2017). Change of school playground environment on bullying: A randomized controlled trial . Pediatrics , 139 ( 5 ), e20163072. 10.1542/peds.2016-3072 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Fekkes, M., Pijpers, F. I. M., & Verloove‐Vanhorick, P. (2006). Effects of antibullying school program on bullying and health complaints . Archives of Pediatrics and Adolescent Medicine , 160 ( 6 ), 638–644. 10.1001/archpedi.160.6.638 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Fekkes, M., van de Sande, M. C. E., Gravesteijn, J. C., Pannebakker, F. D., Buijs, G. J., Diekstra, R. F. W., & Kocken, P. L. (2016). Effects of the Dutch Skills for Life program on the health behaviour, bullying, and suicidal ideation of secondary school students . Health Education , 116 ( 1 ), 2–15. 10.1108/HE-05-2014-0068 [ CrossRef ] [ Google Scholar ]
• Finn, K.O'K. (2009). An evaluation of the Olweus Bullying Prevention Program . Retrieved from ProQuest Dissertations Publishing (3343406).
• Fonagy, P., Twemlow, S. W., Vernberg, E. M., Nelson, J. M., Dill, E. J., Little, T. D., & Sargent, J. A. (2009). A cluster randomized controlled trial of child‐focused psychiatric consultation and a school systems‐focused intervention to reduce aggression . The Journal of Child Psychology and Psychiatry , 50 ( 5 ), 607–616. 10.1111/j.1469-7610.2008.02025.x [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Fox, C., & Boulton, M. (2003). Evaluating the effectiveness of a social skills training (SST) program for victims of bullying . Educational Research , 45 , 231–247. [ Google Scholar ]
• Frey, K., Hirschstein, M. K., Snell, J. L., van Schoiack Edstrom, L., MacKenzie, E. P., & Broderick, C. J. (2005). Reducing playground bullying and supporting beliefs: An experimental trial of the Steps to Respect program . Developmental Psychology , 41 , 479–491. [ PubMed ] [ Google Scholar ]
• Garaigordobil, M., & Martínez‐Valderrey, V. (2015). Effects of Cyberprogram 2.0 on “face‐to‐face” bullying, cyberbullying and empathy . Psciothema , 27 ( 1 ), 45–51. 10.7334/psciotherma2014.78 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Gini, G., Belli, B., & Casagrande, M. (2003). Le prepotenze a scuola: Una esperienza di ricerca‐intervento antibullisimo [Bullying at school: An experience of research‐intervention against bullying] . Eta Evolutiva , 76 , 33–45. [ Google Scholar ]
• Gollwitzer, M., Eisenbach, K., Atria, M., Strohmeier, D., & Banse, R. (2006). Evaluation of aggression‐reducing effects of the “Viennese Social Competence Training” . Swiss Journal of Psychology , 65 , 125–135. [ Google Scholar ]
• Herrick, C. (2012). An investigation into the effectiveness of an anti‐bullying campaign (Doctoral Dissertation). University of Nottingham, UK.
• Holen, S., Waaktaar, T., Lervåg, A., & Ystgaard, M. (2013). Implementing a universal stress management program for young school children: Are there classroom climate or academic effects? Scandinavian Journal of Educational Research , 57 ( 4 ), 420–444. 10.1080/00313831.2012.656320 [ CrossRef ] [ Google Scholar ]
• Hunt, C. (2007). The effect of an education program on attitudes and beliefs about bullying and bullying behaviour in junior secondary school students . Child and Adolescent Mental Health , 12 ( 1 ), 21–26. [ PubMed ] [ Google Scholar ]
• Jenson, J. M., Brisson, D., Bender, K. A., & Williford, A. P. (2013). Effects of the Youth Matters prevention program on patterns of bullying and victimization in elementary and middle school . Social Work Research , 37 ( 4 ), 361–372. 10.1093/swr/svt030 [ CrossRef ] [ Google Scholar ]
• Jenson, J. M., & Dieterich, W. A. (2007). Effects of a skill‐based prevention program on bullying and bully victimization among elementary school children . Prevention Science , 8 , 285–296. [ PubMed ] [ Google Scholar ]
• Jenson, J. M., Dieterich, W. A., Brisson, D., Bender, K. A., & Powell, A. (2010). Preventing childhood bullying: Findings and lessons from the Denver Public Schools trial . Research on Social Work Practice , 20 ( 5 ), 509–517. 10.1177/1049731509359186 [ CrossRef ] [ Google Scholar ]
• Joronen, K., Konu, A., Rankin, H. S., & Astedt‐Kurki, P. (2011). An evaluation of a drama program to enhance social relationships and anti‐bullying at elementary school: A controlled study . Health Promotion International , 27 ( 1 ), 5–14. 10.1093/heapro/dar012 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Ju, Y., Shuqiong, W., & Wenxin, Z. (2009). Intervention research on school bullying in primary schools . Frontiers of Education in China , 4 , 111–122. 10.1007/s11516-009-0007-0 [ CrossRef ] [ Google Scholar ]
• Kaljee, L., Zhang, L., Langhaug, L., Munjile, K., Tembo, S., Menon, A., Stanton, B., Li, X., & Malungo, J. (2017). A randomized‐controlled trial for the teachers' diploma programme on psychosocial care, support and protection in Zambian government primary schools . Psychology, Health, and Medicine , 22 ( 4 ), 381–392. 10.1080/13548503.2016.1153682 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kärnä, A., Voeten, M., Little, T. D., Alanen, E., Poskiparta, E., & Salmivalli, C. (2013). Effectiveness of the KiVa Antibullying Program: Grades 1–3 and 7–9 . Journal of Educational Psychology , 105 ( 2 ), 535–551. 10.1037/a0030417 [ CrossRef ] [ Google Scholar ]
• Kärnä, A., Voeten, M., Little, T. D., Poskiparta, E., Alanen, E., & Salmivalli, C. (2011a). Going to scale: A nonrandomized nationwide trial of the KiVa antibullying Program for Grades 1–9 . Journal of Consulting and Clinical Psychology , 79 ( 6 ), 796–805. 10.1037/a0025740 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kärnä, A., Voeten, M., Little, T. D., Poskiparta, E., Kaljonen, A., & Salmivalli, C. (2011b). A large‐scale evaluation of the KiVa antibullying program: Grades 4–6 . Child Development , 82 ( 1 ), 311–330. 10.1111/j.1467-8624.2010.01.557.x [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kimber, B., Sandell, R., & Bremberg, S. (2008). Social and emotional training in Swedish classrooms for the promotion of mental health: Results from an effectiveness study in Sweden . Health Promotion International , 23 ( 2 ), 134–143. 10.1093/heapro/dam046 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Knowler, C., & Frederickson, N. (2013). Effects of an emotional literacy intervention for students identified with bullying behaviour . Educational Psychology , 33 ( 7 ), 862–883. 10.1080/01443410.2013.785052 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Krueger, L. M. (2010). The implementation of an anti‐bullying program to reduce bullying behaviours on elementary school buses (Doctoral dissertation). D'Youville College, Buffalo, NY (UMI 3441874).
• Li, K. K., Washburn, I., DuBois, D. L., Vuchinich, S., Ji, P., Brechling, V., Day, J., Beets, M. W., Acock, A. C., Berbaum, M., Snyder, F., & Flay, B. R. (2011). Effects of the Positive Action programme on problem behaviours in elementary school students: A matched‐pair randomised control trial in Chicago . Psychology and Health , 26 ( 2 ), 187–204. 10.1080/08870446.2011.531574 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Losey, R. A. (2009). An evaluation of the Olweus Bullying Prevention Program's effectiveness in a high school setting (Doctoral dissertation). University of Cincinnati, Cincinnati, OH.
• Low, S., & Van Ryzin, M. (2014). The moderating effects of school climate on bullying prevention efforts . School Psychology Quarterly , 29 ( 3 ), 306–319. 10.1037/spq0000073 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Martin, F. D. F., Martinez, M., del, C. P. , & Tirado, J. L. A. (2005). Design, implementation and evaluation of a bullying prevention pilot program. [Spanish: Diseno, aplicacion y evaluacion de un Programa Piloto para la Prevencion del Maltrato entre companeros] . Revista Mexicana de Psicologia , 22 , 375–384. [ Google Scholar ]
• McLaughlin, L. P. (2009). The effect of cognitive behavioral therapy and cognitive behavioral therapy plus media on the reduction of bullying and victimization and the increase of empathy and bystander response in a bully prevention program for urban sixth‐grade students (Doctoral Dissertation). University of Toledo.
• Melton, G. B., Limber, S. P., Flerx, V., Nation, M., Osgood, W., Chambers, J., Henggeler, S., Cunningham, P., & Olweus, D. (1998). Violence among rural youth, Final report to the Office of Juvenile Justice and Delinquency Prevention, Washington, DC.
• Menard, S., & Grotpeter, J. K. (2014). Evaluation of Bully‐Proofing Your School as an elementary school antibullying intervention . Journal of School Violence , 13 ( 2 ), 188–209. 10.1080/15388220.2013.840641 [ CrossRef ] [ Google Scholar ]
• Menard, S., Grotpeter, J., Gianola, D., & O'Neal, M. (2008). Evaluation of Bully Proofing your school: Final report . Downloaded from the NCJRS http://www.ncjrs.gov/pdffiles1/nij/grants/221078.pdf
• Menesini, E., Codescasa, E., Benelli, B., & Cowie, H. (2003). Enhancing children's responsibility to take action against bullying: Evaluation of a befriending intervention in Italian middle schools . Aggressive Behavior , 29 , 1–14. [ Google Scholar ]
• Menesini, E., Nocentini, A., & Palladino, B. E. (2012). Empowering students against bullying and cyberbullying: Evaluation of an Italian peer‐led model . International Journal of Conflict and Violence , 6 ( 2 ), 314–320. [ Google Scholar ]
• Meyer, N., & Lesch, E. (2000). An analysis of the limitations of a behavioural programme for bullying boys from a sub‐economic environment . Southern African Journal of Child and Adolescent Mental Health , 12 ( 1 ), 59–69. [ Google Scholar ]
• Nocentini, A., & Menesini, E. (2015). KiVa antibullying program in Italy: Evidence of effectiveness in a randomized control trial . Prevention Science , 17 ( 8 ), 1012–1023. 10.1007/s11121-016-0690-z [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Olweus, D. (1992). Bullying among school children: Intervention and prevention. In Peters R. D., McMahon R. J. & Quinsey V. L. (Eds.), Aggression and violence throughout the lifespan (pp. 100–125). Sage. [ Google Scholar ]
• Olweus, D. (1993). Bully/victim problems among school children: Long‐term consequences and an effective intervention program. In Hodgins S. (Ed.), Mental disorder and crime (pp. 317–349). Sage. [ Google Scholar ]
• Olweus, D. (1994a). Bullying at school: Basic facts and effects of a school based intervention program . Journal of Child Psychology and Psychiatry , 35 , 1171–1190. [ PubMed ] [ Google Scholar ]
• Olweus, D. (1994b). Bullying at school: Basic facts and an effective intervention programme . Promotion and Education , 1 , 27–31. [ PubMed ] [ Google Scholar ]
• Olweus, D. (1994c). Bullying at school: Long‐term outcome for the victims and an effective school‐based intervention program. In Huesmann L. R. (Ed.), Aggressive behavior: Current perspectives (pp. 97–130). Plenum. [ Google Scholar ]
• Olweus, D. (1995). Peer abuse or bullying at school: Basic facts and a school‐based intervention programme . Prospects , 25 ( 1 ), 133–139. [ Google Scholar ]
• Olweus, D. (1996a). Bullying or peer abuse in school: Intervention and prevention. In Davies G., Lloyd‐Bostock S., McMurran M. & Wilson C. (Eds.), Psychology, law, and criminal justice: International developments in research and practice (pp. 248–267). Walter de Gruyter. [ Google Scholar ]
• Olweus, D. (1996b). Bullying at school: Knowledge base and effective intervention . Annals of the New York Academy of Sciences , 784 , 265–276. [ Google Scholar ]
• Olweus, D. (1996c). Bully/victim problems at school: Facts and effective intervention . Reclaiming Children and Youth: Journal of Emotional and Behavioral Problems , 5 ( 1 ), 15–22. [ Google Scholar ]
• Olweus, D. (1997a). Bully/victim problems in school: Knowledge base and an effective intervention project . Irish Journal of Psychology , 18 , 170–190. [ Google Scholar ]
• Olweus, D. (1997b). Bully/victim problems in schools: Facts and intervention . European Journal of Psychology of Education , 12 , 495–510. [ Google Scholar ]
• Olweus, D. (1997c). Tackling peer victimization with a school‐based intervention program. In Fry D. P. & Bjorkqvist K. (Eds.), Cultural variation in conflict resolution: Alternatives to violence (pp. 215–232). Erlbaum. [ Google Scholar ]
• Olweus, D. (2004a). The Olweus Bullying Prevention Programme: Design and implementation issues and a new national initiative in Norway. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 13–36). Cambridge University Press. [ Google Scholar ]
• Olweus, D. (2004b). Bullying at school: Prevalence estimation, a useful evaluation design, and a new national initiative in Norway . Association for Child Psychology and Psychiatry Occasional Papers , 23 , 5–17. [ Google Scholar ]
• Olweus, D. (2005a). A useful evaluation design, and the effects of the Olweus bullying prevention program . Psychology, Crime and Law , 11 , 389–402. [ Google Scholar ]
• O'Moore, A. M., & Milton, S. J. (2004). Ireland: The Donegal primary school antibullying project. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 275–288). Cambridge University Press. [ Google Scholar ]
• Ortega‐Ruiz, R., Del Rey, R., & Casas, J. A. (2012). Knowing, building and living together on Internet and social networks: The ConRed cyberbullying prevention program . International Journal of Conflict and Violence , 6 ( 2 ), 303–313. [ Google Scholar ]
• Ostrov, J. M., Godleski, S. A., Kamper‐DeMarco, K. E., Blakely‐McClure, S. J., & Celenza, L. (2015). Replication and extension of the early childhood friendship project: Effects on physical and relational bullying . School Pyschology Review , 44 ( 4 ), 445–463. [ Google Scholar ]
• Pagliocca, P. M., Limber, S. P., & Hashima, P. (2007). Evaluation report for the Chula Vista Olweus Bullying Prevention Program . Final report prepared for the Chula Vista Police Department.
• Palladino, B. E., Nocentini, A., & Menesini, E. (2012). Online and offline peer led models against bullying and cyberbullying . Psicothema , 24 ( 4 ), 634–639. [ PubMed ] [ Google Scholar ]
• Palladino, B. E., Nocentini, A., & Menesini, E. (2016). Evidence‐based intervention against bullying and cyberbullying: Evaluation of the NoTrap! program in two independent trials . Aggressive Behavior , 42 ( 2 ), 194–206. 10.1002/ab.21636 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Pepler, D. J., Craig, W. M., O'Connell, P., Atlas, R., & Charach, A. (2004). Making a difference in bullying: Evaluation of a systemic school‐based program in Canada. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 125–140). Cambridge University Press. [ Google Scholar ]
• Polanin, M.K. (2015). Effects of cultural awareness training in conjunction with an established bullying prevention program (Doctoral Dissertation). Loyola University Chicago.
• Pryce, S., & Frederickson, N. (2013). Bullying behaviour, intentions and classroom ecology . Learning Environment Research , 16 , 183–199. 10.1007/s10984-013-9137-7 [ CrossRef ] [ Google Scholar ]
• Rahey, L., & Craig, W. M. (2002). Evaluation of an ecological program to reduce bullying in schools . Canadian Journal of Counselling , 36 , 281–295. [ Google Scholar ]
• Rawana, J. S., Norwood, S. J., & Whitley, J. (2011). A mixed‐method evaluation of a strength‐based bullying prevention program . Canadian Journal of School Psychology , 26 ( 4 ), 283–300. 10.1177/0829573511423741 [ CrossRef ] [ Google Scholar ]
• Rican, P., Ondrova, K., & Svatos, J. (1996). The effect of a short, intensive intervention upon bullying in four classes in a Czech town . Annals of the New York Academy of Sciences , 794 , 399–400. [ Google Scholar ]
• Roland, E., Bru, E., Midthassel, U. V., & Vaaland, G. S. (2010). The Zero programme against bullying: Effects of the programme in the context of the Norwegian manifesto against bullying . Social Psychology of Education , 13 , 41–55. 10.1007/s11218-009-9096-0 [ CrossRef ] [ Google Scholar ]
• Rosenbluth, B., Whitaker, D. J., Sanchez, E., & Valle, L. A. (2004). The Expect Respect Project: Preventing bullying and sexual harassment in US elementary schools. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 211–233). Cambridge University Press. [ Google Scholar ]
• Salmivalli, C., Kaukiainen, A., & Voeten, M. (2005). Anti‐bullying intervention: Implementation and outcome . British Journal of Educational Psychology , 75 , 465–487. [ PubMed ] [ Google Scholar ]
• Salmivalli, C., Kaukiainen, A., Voeten, M., & Sinisammal, M. (2004). Targeting the group as a whole: The Finnish anti‐bullying intervention. In Smith P. K., Pepler D. & Rigby K. (Eds.), Bullying in schools: How successful can interventions be? (pp. 251–275). Cambridge University Press. [ Google Scholar ]
• Sapouna, M., Wolke, D., Vannini, N., Watson, S., Woods, S., Schneider, W., Enz, S., Hall, L., Paiva, A., André, E., Dautenhahn, K., & Aylett, R. (2010). Virtual learning intervention to reduce bullying victimization in primary school: A controlled trial . Journal of Child Psychology and Psychiatry , 51 ( 1 ), 104–112. 10.1111/j.1469-7610.2009.02137.x [ PubMed ] [ CrossRef ] [ Google Scholar ]
• da Silva, J., de Oliveira, W., Braga, I., Farias, M., da Silva Lizzi, E., Gonçalves, M., Pereira, B., & Silva, M. (2016). The effects of a skill‐based intervention for victims of bullying in Brazil . International Journal of Environmental Research and Public Health , 13 , 1042. 10.3390/ijerph13111042 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Solomontos‐Kountouri, O., Gradinger, P., Yanagida, T., & Strohmeier, D. (2016). The implementation and evaluation of the ViSC program in Cyprus: Challenges of cross‐national dissemination and evaluation results . European Journal of Developmental Psychology , 13 ( 6 ), 737–755. 10.1080/17405629.2015.1136618 [ CrossRef ] [ Google Scholar ]
• Spröber, N., Schlottke, P. F., & Hautzinger, M. (2006). ProACT + E: Ein Programm zur Pravention von “bullying” an Schulen und zur Forderung der positiven Entwicklung von Schulern: Evalation eines schulbasierten, universalen, primar‐praventiven Programms fur weiterfuhrende Schulen unter Einbeziehung von Lehrern, Schulern und Eltern. [German: ProACT + E: A programme to prevent bullying in schools and to increase the positive development of students. Evaluation of a school‐based, universal, primary preventive programme for secondary schools that includes teachers, students, and parents] . Zeitschrift fur Klinische Psychologie und Psychotherapie: Forschung und Praxis , 35 , 140–150. [ Google Scholar ]
• Stallard, P., Phillips, R., Montgomery, A., Spears, M., Anderson, R., Taylor, J., Araya, R., Lewis, G., Ukoumunne, O., Millings, A., Georgiou, L., Cook, E., & Sayal, K. (2013). A cluster randomised controlled trial to determine the clinical effectiveness and cost‐effectiveness of classroom‐based cognitive–behavioural therapy (CBT) in reducing symptoms of depression in high‐risk adolescents . Health Technology Assessment , 17 ( 47 ). 10.3310/hta17470 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Strohmeier, D., Hoffmann, C., Schiller, E., Stefanek, E., & Spiel, C. (2012). ViSC Social Competence Program . New Directions for Youth Development , 133 , 71–84. 10.1002/yd.20008 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Sutherland, A. E. (2010). The roles of school climate and peers in bullying (Unpublished doctoral dissertation). Queen's University, Canada.
• Toner, B. K. (2010). The implementation of the bully prevention program: Bully Proofing Your School and its effect on bullying and school climate on sixth grade suburban Students (Doctoral dissertation). Available from the ProQuest Dissertation and Theses database (UMI No. 3414552).
• Topper, L. R. (2011). Bullying victimisation and alcohol‐misuse in adolescence: Investigating the functional relationship and new prevention strategies (Unpublished doctoral dissertation). King's College London, UK.
• Trip, S., Bora, C., Sipos‐Gug, S., Tocai, I., Gradinger, P., Yanagida, T., & Strohmeier, D. (2015). Bullying prevention in schools by targeting cognitions, emotions, and behavior: Evaluating the effectiveness of the REBE‐ViSC program . Journal of Counselling Psychology , 62 ( 4 ), 732–740. 10.1037/cou0000084 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Tsiantis, A. C. J., Beratis, I. N., Syngelaki, E. M., Stefanakou, A., Asimopolous, C., Sideridis, G. D., & Tsiantis, J. (2013). The effects of a clinical prevention program on bullying, victimization, and attitudes toward school of elementary school students . Behavioral Disorders , 38 ( 4 ), 243–257. [ Google Scholar ]
• Waasdorp, T. E., Bradshaw, C. P., & Leaf, P. J. (2012). The impact of schoolwide positive behavioural interventions and supports on bullying and peer rejection . Archives of Pediatric and Adolescent Medicine , 166 ( 2 ), 149–156. 10.1001/archpediatrics.2011.755 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Wang, C., & Goldberg, T. S. (2017). Using children's literature to decrease moral disengagement and victimization among elementary school students . Psychology in the Schools , 54 , 918–931. 10.1002/pits.22042 [ CrossRef ] [ Google Scholar ]
• Whitaker, D. J., Rosenbluth, B., Valle, L. A., & Sanchez, E. (2004). Expect respect: A school‐based intervention to promote awareness and effective responses to bullying and sexual harassment. In Espelage D. L. & Swearer S. M. (Eds.), Bullying in American schools: A social‐ecological perspective on prevention and intervention (pp. 327–350). Erlbaum. [ Google Scholar ]
• Whitney, I., Rivers, I., Smith, P. K., & Sharp, S. (1994). The Sheffield Project: Methodology and findings. In Smith P. K. & Sharp S. (Eds.), School bullying: Insights and perspectives (pp. 20–56). Routledge. [ Google Scholar ]
• Williams, J., Miller, S., Cutbush, S., Gibbs, D., Clinton‐Sherrod, M., & Jones, S. (2015). A latent transition model of the effects of a teen dating violence prevention initiative . Journal of Adolescent Health , 56 , S27–S32. 10.1016/j.jadohealth.2014.08.019 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Yaakub, N. F., Haron, F., & Leong, G. C. (2010). Examining the efficacy of the Olweus prevention programme in reducing bullying: The Malaysian experience . Procedia–Social and Behavioral Sciences , 5 , 595–598. 10.1016/j.sbspro.2010.07.148 [ CrossRef ] [ Google Scholar ]
• Yanagida, T., Strohmeier, D., & Spiel, C. (2019). Dynamic change of aggressive behavior and victimization among adolescents: Effectiveness of the ViSC program . Journal of Clinical Child & Adolescent Psychology , 48 , S90–S104. 10.1080/15374416.2016.1233498 [ PubMed ] [ CrossRef ] [ Google Scholar ]

REFERENCES TO EXCLUDED STUDIES

• Ahtola, A., Haataja, A., Kärnä, A., Poskiparta, E., & Salmivalli, C. (2013). Implementation of anti‐bullying lessons in primary classrooms: How important is head teacher support? Educational Research , 55 ( 4 ), 376–392. 10.1080/00131881.2013.844941 [ CrossRef ] [ Google Scholar ]
• Ahtola, A., Haataja, A., Kärnä, A., Poskiparta, E., & Salmivalli, C. (2012). For children only? Effects of the KiVa antibullying program on teachers . Teaching and Teacher Education , 28 , 851–859. 10.1016/j.tate.2012.03.006 [ CrossRef ] [ Google Scholar ]
• DeSmet, A., Bastiaensens, S., Van Cleemput, K., Poels, K., Vandebosch, H., Deboutte, G., Herrewijn, L., Malliet, S., Pabian, S., Van Broeckhoven, F., De Troyer, O., Deglorie, G., Van Hoecke, S., Samyn, K., & De Bourdeaudhuij, I. (2018). The efficacy of the Friendly Attac serious digitial game to promote prosocial bystander behavior in cyberbullying among young adolescents: A cluster‐randomized controlled trial . Computers in Human Behavior , 78 , 336–347. 10.1016/j.chb.2017.10.011 [ CrossRef ] [ Google Scholar ]
• Del Rey, R., Casas, J. A., & Ortega, R. (2015). The impacts of the ConRed program on different cyberbullying roles . Aggressive Behavior , 42 ( 2 ), 123–135. 10.1002/ab.21608 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Earhart, J. A., Jr. (2011). Promoting positive peer relationships among youths: A study examining the effects of a class‐wide bullying prevention program (Doctoral dissertation). University of California, Santa Barbara. Retrieved from: ProQuest dissertations publishing (no. 3481964).
• Espelage, D. L., Rose, C. H., & Polanin, J. R. (2015). Social‐emotional learning program to reduce bullying, fighting, and victimization among middle school students with disabilities . Remedial and Special Education , 36 , 1–13. 10.1177/0741932514564564 [ CrossRef ] [ Google Scholar ]
• Fletcher, A., Fitzgerald‐Yau, N., Wiggins, M., Viner, R. M., & Bonell, C. (2015). Involving young people in changing their school environment to make it safer: Findings from a process evaluation in English secondary schools . Health Education , 115 ( 3‐4 ), 322–338. 10.1108/HE-04-2014-0063 [ CrossRef ] [ Google Scholar ]
• Frey, K. S., Hirschstein, M. K., Edstrom, L. V., & Snell, J. L. (2009). Observed reductions in school bullying, nonbullying aggression, and destructive bystander behavior: A longitudinal evaluation . Journal of Educational Psychology , 101 ( 2 ), 466–481. 10.1037/a0013839 [ CrossRef ] [ Google Scholar ]
• Garandeau, C. F., Lee, I. A., & Salmivalli, C. (2014). Differential effects of the KiVa anti‐bullying program on popular and unpopular bullies . Journal of Applied Developmental Psychology , 35 ( 1 ), 44–50. 10.1016/j.appdev.2013.10.004 [ CrossRef ] [ Google Scholar ]
• Garandeau, C. F., Poskiparta, E., & Salmivalli, C. (2014). Tackling acute cases of school bullying in the KiVa anti‐bullying program: A comparison of two approaches . Journal of Abnormal Child Psychology , 42 , 981–991. 10.1007/s10802-014-9861-1 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Giesbrecht, G. F., Leadbeater, B. J., & MacDonald, S. W. S. (2011). Child and context characteristics in trajectories of physical and relational victimization among early elementary school children . Development and Psychopathology , 23 , 239–252. 10.1017/S09545739410000763 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Gradinger, P., Yanagida, T., Strohmeier, D., & Spiel, C. (2015). Prevention of cyberbullying and cyber victimization: Evaluation of the ViSC Social Competence program . Journal of School Violence , 14 ( 1 ), 87–110. 10.1080/15388220.2014.96323 [ CrossRef ] [ Google Scholar ]
• Haataja, A., Voeten, M., Boulton, A. J., Ahtola, A., Poskiparta, E., & Samlivalli, C. (2014). The KiVa antibullying curriculum and outcome: Does fidelity matter? Journal of School Psychology , 52 , 479–493. 10.1016/j.jsp.2014.07.001 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Harpin, S. B. (2011). Missingness in longitudinal research: Attrition analysis and imputation approaches in a school‐based study of young adolescents (Doctoral Dissertation). University of Minnesota.
• Hutchings, J., & Clarkson, S. (2015). Introducing and piloting the KiVa bullying prevention programme in the UK . Educational and Child Psychology , 32 ( 1 ), 49–61. [ Google Scholar ]
• Kyriakides, L., Creemers, B. P. M., Muijs, D., Rekers‐Mombarg, L., van Petegem, P., & Pearson, D. (2014). Using the dynamic model of educational effectiveness to design strategies and actions to face bullying . School Effectiveness and School Improvement , 25 ( 1 ), 83–104. 10.1080/09243453.2013.771686 [ CrossRef ] [ Google Scholar ]
• Leff, S. S., Waasdorp, T. E., Paskewich, B., Gullan, R. L., Jawad, A. F., Paquette MacEvoy, J., Feinberg, B. E., & Power, T. J. (2010). The Preventing Relational Aggression in School Everyday program: A preliminary evaluation of acceptability and impact . School Psychology Review , 39 ( 4 ), 569–587. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Lewis, K. M., Schure, M. B., Bavarian, N., DuBois, D. L., Day, J., Ji, P., Silverthorn, N., Acock, A., Vuchinich, S., & Flay, B. R. (2013). Problem behavior and urban, low‐income youth: A randomized controlled trial of Positive Action in Chicago . American Journal of Preventive Medicine , 44 ( 6 ), 622–630. 10.1016/j.amepre.2013.01.030 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lishak, N. (2011). Examination of bullying behaviours and the implementation of a social norms project in a middle school (Doctoral Dissertation). Walden University. (UMI 3454156).
• Low, S., Van Ryzin, M. J., Brown, E. C., Smith, B. H., & Haggerty, K. P. (2014). Engagement matters: Lessons from assessing classroom implementation of Steps to Respect: A bullying prevention program over a one‐year period . Prevention Science , 15 , 165–176. 10.1007/s11121-012-0359-1 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Noland, B. (2011). Effects of the KiVa anti‐bullying program on adolescents' perceptions of peers, depression, and anxiety (Unpublished doctoral dissertation). Kansas: University of Kansas.
• van der Ploeg, R., Steglich, C., & Veenstra, R. (2016). The support group approach in the Dutch KiVa anti‐bullying programme: Effects on victimization, defending and well‐being at school . Educational Research , 58 ( 3 ), 221–236. 10.1080/00131881.2016.1884949 [ CrossRef ] [ Google Scholar ]
• Şahin, M. (2012). An investigation into the efficiency of empathy training program on preventing bullying in primary schools . Children and Youth Services Review , 34 , 1325–1330. 10.1016/j.childyouth.2012.03.013 [ CrossRef ] [ Google Scholar ]
• Sainio, M., Veenstra, R., Huitsing, G., & Salmivalli, C. (2012). Same‐ and other‐sex victimization: Are the risk factors similar? Aggressive Behavior , 38 , 422–455. 10.1002/ab.21445 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Salmivalli, C., Kärnä, A., & Poskiparta, E. (2012). Counteracting bullying in Finland: The KiVa program and its effects on different forms of being bullied . International Journal of Behavioral Development , 35 ( 5 ), 405–411. 10.1177/0165025411407457 [ CrossRef ] [ Google Scholar ]
• Schroeder, B. A., Messina, A., Schroeder, D., Good, K., Barto, S., Saylor, J., & Masiello, M. (2012). The implementation of a statewide bullying prevention program: Preliminary findings from the field and the importance of coalitions . Health promotion practice , 13 ( 4 ), 49–495. 10.1177/1524839910386887 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Stevens, V., de Bourdeaudhuij, I., & van Oost, P. (2000). Bullying in Flemish schools: An evaluation of anti‐bullying intervention in primary and secondary schools . British Journal of Educational Psychology , 70 , 195–210. [ PubMed ] [ Google Scholar ]
• Watson, S. E. J., Vannini, N., Woods, S., Dautenhahn, K., Sapouna, M., Enz, S., Schneider, W., Wolke, D., Hall, L., Paiva, A., André, E., & Aylett, R. (2010). Inter‐cultural differences in response to a computer‐based anti‐bullying intervention . Educational Research , 52 ( 1 ), 61–80. 10.1080/001318811003588261 [ CrossRef ] [ Google Scholar ]
• Williford, A., Boulton, A., Noland, B., Little, T. D., Kärnä, A., & Salmivalli, C. (2012). Effects of the KiVa anti‐bullying program on adolescents' depression, anxiety, and perception of peers . Journal of Abnormal Child Psychology , 40 , 289–300. 10.1007/s10802-011-9551-1 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Williford, A., Elledge, L. C., Boulton, A. J., DePaolis, K. J., Little, T. D., & Salmivalli, C. (2013). Effects of the KiVa anti‐bullying program on cyberbullying and cybervictimization frequency among Finnish youth . Journal of Clinical Child and Adolescent Psychology , 42 ( 6 ), 820–833. 10.1080/15374416.2013.787623 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Wölfer, R., & Scheithauer, H. (2014). Social influence and bullying behavior: Intervention‐based network dynamics of the fairplayer.manual bullying prevention program . Aggressive Behavior , 40 , 309–319. 10.1002/ab.21524 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Wong, D. S. W., Cheng, C. H. K., Ngan, R. M. H., & Ma, S. K. (2011). Program effectiveness of a restorative whole‐school approach for tackling school bullying in Hong Kong . International Journal of Offender Therapy and Comparative Criminology , 55 ( 6 ), 846–862. 10.1177/0306624X10374638 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Wurf, G. (2012). High school anti‐bullying interventions: An evaluation of curriculum approaches and the method of Shared Concern in four Hong Kong international schools . Australian Journal of Guidance and Counselling , 22 ( 1 ), 139–149. 10.1017/jgc.2012.2 [ CrossRef ] [ Google Scholar ]
• Yang, A., & Salmivalli, C. (2015). Effectiveness of the KiVa antibullying programme on bully‐victims, bullies and victims . Educational Research , 57 ( 1 ), 80–90. 10.1080/00131881.2014.983724 [ CrossRef ] [ Google Scholar ]

ADDITIONAL REFERENCES

• Ajzen, I. (1991). The theory of planned behaviour . Organisational Behaviour and Human Decision Processes , 50 , 179–211. [ Google Scholar ]
• Altinay, D. (2003). Psycho‐dramatic group therapy . Istanbul: System Publishing. [ Google Scholar ]
• Arseneault, L., Bowes, L., & Shakoor, S. (2010). Bullying victimization in youths and mental health problems: ‘Much ado about nothing'? Psychological Medicine , 40 ( 5 ), 717–729. [ PubMed ] [ Google Scholar ]
• Atria, M., & Spiel, C. (2007). Viennese Social Competence (ViSC) training for students: Program and Evaluation. In Maher C. A., Zins J. & Elias M. (Eds.), Bullying, Victimization, and Peer Harassment: A Handbook of Prevention and Intervention (pp. 179–197). Routledge. [ Google Scholar ]
• Ayieko, J., Abuogi, L., Simchowitz, B., Bukusi, E. A., Smith, A. H., & Reingold, A. (2014). Efficacy of isoniazid prophylactic therapy in prevention of tuberculosis in children: A meta‐analysis . BMC Infectious Diseases , 14 ( 1 ), 91. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Baldry, A. C., Farrington, D. P., & Sorrentino, A. (2017). School bullying and cyberbullying among boys and girls: Roles and overlap . Journal of Aggression, Maltreatment, & Trauma , 26 ( 9 ), 937–951. 10.1080/10926771.2017.1330793 [ CrossRef ] [ Google Scholar ]
• Baldry, A. C., Sorrentino, A., & Farrington, D. P. (2019). Cyberbullying and cybervictimization versus parental supervision, monitoring and control of adolescents' online activities . Children and Youth Services Review , 96 , 302–307. 10.1016/j.childyouth.2018.11.058 [ CrossRef ] [ Google Scholar ]
• Bandura, A. (1978). Social learning theory of aggression . Journal of Communication , 28 ( 3 ), 12–29. 10.1111/j.1460-2466.1978.tb01621.x [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Bloom, H. S., Hill, C. J., & Riccio, J. A. (2003). Linking program implementation and effectiveness: Lessons from a pooled sample of welfare‐to‐work experiments . Journal of Policy Analysis and Management , 22 ( 4 ), 551–575. [ Google Scholar ]
• Brighi, A., Ortega, R., Pyzalski, J., Scheithauer, H., Smith, P.K., Tsormpatzoudis, C., Barkoukis, V., Del Rey, R., & Thompson, J. (2012). European Cyberbullying Intervention Project Questionnaire (ECIPQ) . Unpublished manuscript. Bologna, Italy: University of Bologna.
• Borenstein, M., Hedges, L. V., Higgins, J. P. T., & Rothstein, H. R. (2009). Introduction to meta‐analysis . Wiley Ltd. [ Google Scholar ]
• Bronfenbrenner, U. (1979). Ecology of human development: Experiments by nature and design . Harvard University Press. [ Google Scholar ]
• Cantone, E., Piras, A. P., Vellante, M., Preti, A., Daníelsdóttir, S., D'Aloja, E., Lesinskiene, S., Angermeyer, M. C., Carta, M. G., & Bhugra, D. (2015). Interventions on bullying and cyberbullying in schools: A systematic review . Clinical Practice & Epidiology in Mental Health , 11 ( Suppl 1 M4 ), 58–76. 10.2174/174501791511010058 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Carlos‐Wallace, F. M., Zhang, L., Smith, M. T., Rader, G., & Steinmaus, C. (2016). Parental, in utero, and early‐life exposure to benzene and the risk of childhood leukaemia: A meta‐analysis . American Journal of Epidemiology , 183 ( 1 ), 1–14. 10.1093/aje/kwv120 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Cavell, T. A., & Hughes, J. N. (2000). Secondary prevention as context for assessing change processes in aggressive children . Journal of School Psychology , 38 , 199–236. [ Google Scholar ]
• Chalamandaris, A., & Piette, D. (2015). School‐based anti‐bullying interventions: Systematic review of the methodology to assess their effectiveness . Aggression and Violent Behavior , 24 , 131–174. 10.1016/j.avb.2015.04.004 [ CrossRef ] [ Google Scholar ]
• Centers for Disease Control and Prevention . (2014). Bullying surveillance among school‐ aged children: Uniform definitions and recommended data elements . Washington, DC: Centers for Disease Control and Prevention (CDC). [ Google Scholar ]
• Combs, A. (1962). The self in chaos . PsycCRITIQUES , 7 ( 2 ), 53–54. [ Google Scholar ]
• Creemers, B. P. M., & Kyriakides, L. (2008). The dynamics of educational effectiveness: A contribution to policy, practice and theory in contemporary schools . Routledge. [ Google Scholar ]
• Creemers, B. P. M., & Kyriakides, L. (2012). Improving quality in education: Dynamic approaches to school improvement . Routledge. [ Google Scholar ]
• van Dam, D. S., van der Ven, E., Velthorst, E., Selten, J. P., Morgan, C., & de Haan, L. (2012). Childhood bullying and the association with psychosis in non‐clinical and clinical samples: A review and meta‐analysis . Psychological Medicine , 42 , 2463–2474. [ PubMed ] [ Google Scholar ]
• Department for Education and Skills . (2005). Excellence and enjoyment: Social and emotional aspects of learning . London: Author. [ Google Scholar ]
• Diekstra, R. F. W. (1996). Keerpunten: Naar een preventief jeugbeleid (Turning Points: Towards preventive youth policy) . Municipal Authority Greater City of Rotterdam (GCD) .
• Donner, A., & Klar, N. (2002). Issues in meta‐analysis of cluster randomized trials . Statistics in Medicine , 21 , 2971–2980. 10.1002/sim.1301 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Donner, A., Piaggio, G., & Villar, J. (2001). Statistical methods for the meta‐analysis of cluster randomized trials . Statistical Methods in Medical Research , 10 , 325–338. 10.1191/096228001680678322 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Dorjee, K., Choden, T., Baxi, S. M., Steinmaus, C., & Reingold, A. L. (2018). Risk of cardiovasculat disease associated with exposure to abacavir among individuals with HIV: A systematic review and meta‐analyses of results from 17 epidemiological studies . International Journal of Antimicrobial Agents , 52 , 541–553. [ PMC free article ] [ PubMed ] [ Google Scholar ]
• Duckworth, A. L., Steen, T. A., & Seligman, M. E. P. (2005). Positive psychology in clinical practice . Annual Review of Clinical Psychology , 1 , 629–651. [ PubMed ] [ Google Scholar ]
• Easterbrook, P. J., Gopalan, R., Berlin, J. A., & Matthews, D. R. (1991). Publication bias in clinical research . The Lancet , 337 ( 8746 ), 867–872. 10.1016/0140-6736(91)90201-Y [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Eisner, M., & Humphreys, D. (2012). Measuring conflict of interest in prevention and intervention research: A feasibility study. In T. Bliesener, A. Beelmann, & M. Stemmler (Eds.), Antisocial Behavior and Crime , (pp. 165 – 180). Hogrefe.
• Ellis, A. (1962). Reason and emotion in psychotherapy . Stuart. [ Google Scholar ]
• Ellis, P. D. (2010). The Essential Guide to Effect sizes: Statistical power, Meta‐analysis, and the interpretation of research results . Cambridge University Press. [ Google Scholar ]
• Erren, T. C., Glende, C. B., Morfeld, P., & Piekarski, C. (2009). Is exposure to silica associated with lung cancer in the absence of silicosis? A meta‐analytical approach to an important public health question . International Archives of Occupational and Environmental Health , 82 ( 8 ), 997–1004. 10.1007/s00420-008-0381-0 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Espelage, D., & Horne, A. (2008). School violence and bullying prevention: From research based explanations to empirically based solutions. In Brown S. & Lent R. (Eds.), Handbook of Counselling psychology (4 th edition, pp. 588–606). Wiley and Sons. [ Google Scholar ]
• Evans, C. B. R., Fraser, M. W., & Cotter, K. L. (2014). The effectiveness of school‐based bullying prevention programs: A systematic review . Aggression and Violent Behavior , 19 ( 5 ), 532–544. 10.1016/j.avb.2014.07.004 [ CrossRef ] [ Google Scholar ]
• Farrington, D. P. (1983). Randomized experiments on crime and justice . Crime and Justice , 4 , 257–308. [ Google Scholar ]
• Farrington, D. P. (1993). Understanding and preventing bullying . Crime and Justice: A Review of Research , 17 , 381–458. [ Google Scholar ]
• Farrington, D. P. (2003). Methodological quality standards for evaluation research . The Annals of the American Academy of Political and Social Science , 587 ( 1 ), 49–68. [ Google Scholar ]
• Farrington, D. P., Lösel, F., Ttofi, M. M., & Theodorakis, N. (2012). School bullying, depression and offending behavior later in life: An updated systematic review of longitudinal studies . Stockholm: Swedish National Council for Crime Prevention. [ Google Scholar ]
• Farrington, D. P., & Petrosino, A. (2001). The Campbell Collaboration crime and justice group . ANNALS of the American Academy of Political and Social Science , 578 ( 1 ), 35–49. 10.1177/000271620157800103 [ CrossRef ] [ Google Scholar ]
• Farrington, D. P., & Ttofi, M. M. (2009). School‐based programs to reduce bullying and victimization . Campbell Systematic Reviews , 6 , 1–148. 10.4073/csr.2009.6 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Farrington, D. P., & Welsh, B. C. (2008). Saving children from a life of crime: Early risk factors and effective interventions . Oxford University press. [ Google Scholar ]
• Farrington, D. P., & Welsh, B. C. (2013). Measuring effect size in meta‐analysis, with special reference to area‐based crime prevention programs and the effects of closed‐circuit television on crime. In Kuhn A., Schwarzenegger C., Margot P., Donatsch A., Aebi M. & Jositsch D. (Eds.), Criminology, criminal policy and criminal law from an international perspective (pp. 75–89). Stampfli. [ Google Scholar ]
• Faupel, A. (2003). Emotional literacy assessment and intervention ages 7‐11 . NFER Nelson.
• Ferguson, C. J., Miguel, C. S., Kilburn, J. C., & Sanchez, P. (2007). The effectiveness of school‐based anti‐bullying programmes: A meta‐analytic review . Criminal Justice Review , 32 , 401–414. [ Google Scholar ]
• Flay, B. R., & Allred, C. G. (2010). The Positive Action program: Improving academics, behavior, and character by teaching comprehensive skills for successful learning and living. In Lovat T., Toomey R. & Clement N. (Eds.), International Research Handbook on Values Education and Student Wellbeing (pp. 471–501). Springer. [ Google Scholar ]
• Gaffney, H., Farrington, D. P., Espelage, D. L., & Ttofi, M. M. (2018). Are cyberbullying intervention and prevention programs effective? A systematic and meta‐analytical review . Aggression and Violent Behavior , 45 , 134–153. [ Google Scholar ]
• Gaffney, H., Ttofi, M. M., & Farrington, D. P. (2018). Evaluating the effectiveness of school‐bullying prevention programs: An updated meta‐analytical review . Aggression and Violent Behavior , 45 , 111–133. [ Google Scholar ]
• Gastic, B. (2008). School truancy and the disciplinary problems of bullying victims . Educational Review , 60 ( 4 ), 391–404. 10.1080/00131910802393423 [ CrossRef ] [ Google Scholar ]
• Geel, M., , van Goemans, A. , & Vedder, P. H. (2016). The relation between peer victimization and sleeping problems: A meta‐analysis . Sleep medicine reviews , 27 , 89–95. 10.1016/j.smrv.2015.05.004 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Geel, M., , van Vedder, P. , & Tanilon, J. (2014). Bullying and weapon carrying: A meta‐analysis . JAMA Pediatrics , 168 , 714–720. [ PubMed ] [ Google Scholar ]
• Gini, G., & Pozzoli, T. (2013). Bullied children and psychosomatic problems: A meta‐analysis . Pediatrics , 132 , 720–729. [ PubMed ] [ Google Scholar ]
• Gini, G., Pozzoli, T., Lenzi, M., & Vieno, A. (2014). Bullying victimization at school and headache: A meta‐analysis of observational studies . Headache , 54 , 976–986. [ PubMed ] [ Google Scholar ]
• Gravesteijn, J. C., & Diekstra, R. F. W. (2013). Skills for Life, docentenhandleiding, teachers manual . EduActief. [ Google Scholar ]
• Haggas, L. S. (2006). A bully prevention challenge course curriculum (Unpublished master's professional project). Western Oregon University.
• Hawker, D. S. J., & Boulton, M. J. (2000). Twenty years' research on peer victimization and psychosocial maladjustment: A meta‐analytic review of cross‐sectional studies . Journal of Child Psychology and Psychiatry , 41 , 441–455. [ PubMed ] [ Google Scholar ]
• He, J., Van de Vijver, F. J., Dominguez Espinosa, A., Abubakar, A., Dimitrova, R., Adams, B. G., & Fischer, R. (2015). Socially desirable responding: Enhancement and denial in 20 countries, Cross‐Cultural Research ( 49 , pp. 227–249. 3 . [ Google Scholar ]
• Hedges, L. V. (1982). Estimation and testing for differences in effect size: Comment on Hsu . Psychological Bulletin , 91 , 391–393. [ Google Scholar ]
• Higgins, J. P. T., Deeks, J. J., & Altman, D. G. (2011). Special topics in statistics. In Higgins J. P. T. & Green S. (Eds.), Cochrane handbook for systematic reviews of interventions (pp. 481–530). John Wiley & Sons Ltd. [ Google Scholar ]
• Hirschstein, M. K., & Frey, K. S. (2007). Promoting behaviors and beliefs that reduce bullying. The Steps to Respect program. In Jimerson S. R. & Furlong M. J. (Eds.), The handbook of school violence and school safety: From research to practice . Erlbaum. [ Google Scholar ]
• Holt, M. K., Vivolo‐Kantor, A. M., Polanin, J. R., Holland, K. M., DeGue, S., Matjasko, J. L., Wolfe, M., & Reid, G. (2015). Bullying and suicidal ideation and behaviors: A meta‐analysis . Pediatrics , 135 ( 2 ), e496–e509. 10.1542/peds.2014-1864 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Hopkins, B. (2004). Just Schools: A whole school approach to restorative justice . Jessica Kingsley. [ Google Scholar ]
• Jiménez‐Barbero, J. A., Ruiz Hernández, J. A., Llor‐Esteban, B., & Pérez‐García, M. (2012). Effectiveness of antibullying school programmes: A systematic review by evidence levels . Children and Youth Services Review , 34 ( 9 ), 1646–1658. 10.1016/j.childyouth.2012.04.025 [ CrossRef ] [ Google Scholar ]
• Jiménez‐Barbero, J. A., Ruiz‐Hernández, J. A., Llor‐Zaragoza, L., Pérez‐García, M., & Llor‐Esteban, B. (2016). Effectiveness of anti‐bullying school programs: A meta‐analsysis . Children and Youth Services Review , 61 , 165–175. 10.1016/j.childyouth.2015.12.015 [ CrossRef ] [ Google Scholar ]
• Kaminski, J. W., Valle, L. A., Filene, J. H., & Boyle, C. L. (2008). A meta‐analytic review of components associated with parent training program effectiveness . Journal of Abnormal Child Psychology , 36 , 567–589. 10.1007/s10802-007-9201-9 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kochenderfer, B. J., & Ladd, G. W. (2000). Victimized children's responses to peers’ aggression: Behaviors associated with reduced versus continued victimization . Development and Psychopathology , 9 , 59–73. [ PubMed ] [ Google Scholar ]
• Kyriakides, L. (2008). Testing the validity of the comprehensive model of educational effectiveness: A step towards the development of a dynamic model of effectiveness . School Effectiveness and School Improvement , 19 ( 4 ), 429–446. [ Google Scholar ]
• Kyriakides, L., Creemers, B. P. M., Papastylianou, D., & Papadatou‐Pastou, M. (2014). Improving the school learning environment to reduce bullying: An experimental study . Scandinavian Journal of Educational Research , 58 ( 4 ), 453–478. 10.1080/00313831.2013.773556 [ CrossRef ] [ Google Scholar ]
• Lipsey, M. W., & Wilson, D. B. (2001). Practical meta‐analysis . Sage. [ Google Scholar ]
• Littell, J. H., Corcoran, J., & Pillai, V. (2008). Systematic reviews and meta‐analysis . Oxford University Press. [ Google Scholar ]
• Masiello, M. G., & Schroeder, D. (2014). A public health approach to bullying prevention . APHA Press. 10.2105/9780875530413 [ CrossRef ] [ Google Scholar ]
• McAuley, L., Tugwell, P., & Moher, D. (2000). Does the inclusion of grey literature influence estimates of intervention effectiveness reported in meta‐analysis? The Lancet , 356 ( 9237 ), 1228–1231. [ PubMed ] [ Google Scholar ]
• Mishara, B. L., & Ystgaard, M. (2006). Effectiveness of a mental health promotion program to improve coping skills in young children: “Zippy's Friends” . Early Childhood Research Quarterly , 21 ( 1 ), 110–123. [ Google Scholar ]
• Modecki, K. L., Minchin, J., Harbaugh, A. G., Guerra, N. G., & Runions, K. C. (2014). Bullying prevalence across contexts: A meta‐analysis measuring cyber and traditional bullying . Journal of Adolescent Health , 55 , 602–611. 10.1016/j.adohealth.2014.06.007 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Morrison, B. (2002). Bullying and victimization in schools: A restorative justice approach . Australian Institute of Criminology: Trends and Issues , 219 , 1–6. [ Google Scholar ]
• Murray, D. M., & Blitstein, J. L. (2003). Methods to reduce the impact of intraclass correlation in group‐randomized trials . Evaluation Review , 27 , 79–103. 10.1177/0193841x02239019 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Murphy, E., & Lewers, R. (2000). The hidden hurt . Wizard Books. [ Google Scholar ]
• Olweus, D. (1986). The Olweus bully/victim questionnaire . University of Bergen. [ Google Scholar ]
• Olweus, D. (1991). Bully/victim problems among school children: Basic facts and effects of a school‐based intervention program . In Pepler D. J. & Rubin K. H. (Eds.), The Development and Treatment of Childhood Aggression, (pp. 411–448) . Erlbaum. [ Google Scholar ]
• Olweus, D. (1996). The revised Olweus bully/victim questionnaire . Mimeo. Bergen, Norway: Research Center for Health Promotion (HEMIL Center), University of Bergen. [ Google Scholar ]
• Olweus, D., & Limber, S. P. (2017). Some problems with cyberbullying research . Current Opinion in Psychology , 19 , 139–143. [ PubMed ] [ Google Scholar ]
• Ostrov, J. M., & Kamper, K. E. (2015). Future directions for research on the development of relational and physical peer victimization . Journal of Clinical Child and Adolescent Psychology , 44 , 509–519. 10.1080/15374416.2015.1012733 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Owens, A., & Barber, K. (1998). Draama toimii , [Dramaworks]. Helsinki, Finland: JB‐kustannus. [ Google Scholar ]
• Perkins, W. H. (2003). The social norms approach to preventing school and college age substance abuse . Jossey‐Bass. [ Google Scholar ]
• Pikas, A. (2002). New developments of the Shared Concern method . School Psychology International , 23 ( 3 ), 307–326. [ Google Scholar ]
• Piquero, A. R., Jennings, W. G., Diamond, B., Farrington, D. P., Tremblay, R. E., Welsh, B. C., & Reingle Gonzalez, J. M. (2016). A meta‐analysis update on the effects of early family/parent training programs on antisocial behaviour and delinquency . Journal of Experimental Criminology , 12 , 229–248. 10.1007/s11292-016-9256-0 [ CrossRef ] [ Google Scholar ]
• Portnoy, J., & Farrington, D. P. (2015). Resting heart rate and antisocial behavior: An updated systematic review and meta‐analysis . Aggression and Violent Behavior , 22 , 33–45. 10.1016/j.avb.2015.02.004 [ CrossRef ] [ Google Scholar ]
• Purkey, W. W. (1970). Self concept and school achievement . Prentice Hall. [ Google Scholar ]
• Purkey, W. W., & Novak, J. M. (1996). Inviting school success: A self‐concept approach to teaching, learning, and democratic practice . Wadsworth. [ Google Scholar ]
• Resnik, M. D. (2000). Protective factors, resiliency, and healthy youth development . Adolescent medicine: State of the art reviews , 11 ( 1 ), 157–164. [ PubMed ] [ Google Scholar ]
• Rigby, K., & Johnson, B. (2006). Expressed readiness of Australian schoolchildren to act as bystanders in support of children who are being bullied . Educational psychology , 26 ( 3 ), 425–440. [ Google Scholar ]
• Roland, E., & Galloway, D. (2004). Professional cultures in schools with high and low rates of bullying . School effectiveness and school improvement , 15 ( 3‐4 ), 241–260. 10.1080/09243450512331383202 [ CrossRef ] [ Google Scholar ]
• Salmivalli, C. (2010). Bullying and the peer group: A review . Aggression and Violent Behavior , 15 ( 2 ), 112–120. 10.1016/j.avb.2015.10.001 [ CrossRef ] [ Google Scholar ]
• Salmivalli, C., Lagerspertz, K., Björkqvist, K., Österman, K., & Kaukiainen, A. (1996). Bullying as a group process: Participant roles and their relations to social status within the group . Aggressive Behavior , 22 , 1–15. [ Google Scholar ]
• Schultze‐Krumbholz, A., Wölfer, R., Jäkel, A., Zagorscak, P., & Scheithauer, H. (2012). Effective prevention of cyberbullying in Germany: The Medienhelden program. Paper presented at the 10 th ISRA World Meeting, Luxembourg.
• Seligman, M. E., & Csikszentmihalyi, M. (2000). Positive psychology . American Psychologist , 55 ( 1 ), 5–14. [ PubMed ] [ Google Scholar ]
• Sercombe, H., & Donnelly, B. (2013). Bullying and agency: Definition, intervention and ethics . Journal of Youth Studies , 16 ( 4 ), 491–502. [ Google Scholar ]
• Sieving, R. E., & Widome, R. (2008). Toward preventing youth violence: Engaging urban middle‐school students in community service learning . CURA Reporter , 38 ( 1 ), 12–17. [ Google Scholar ]
• Sismani, E., Paradeisioti, A., & Lazarou, C. (2014). Bullying phenomenon and preventive programs in Cyprus's school system . International Journal of Mental Health Promotion , 16 ( 1 ), 67–80. 10.1080/14623730.2014.888894 [ CrossRef ] [ Google Scholar ]
• Smith, P. K., Ananiadou, K., & Cowie, H. (2003). Interventions to reduce school bullying . The Canadian Journal of Psychiatry , 48 ( 9 ), 591–599. [ PubMed ] [ Google Scholar ]
• Smith, P. K., Cowie, H., Olafsson, R. F., & Liefooghe, A. P. (2002). Definitions of bullying: A comparison of terms used, and age and gender differences, in a Fourteen–Country international comparison . Child Development , 73 ( 4 ), 1119–1133. [ PubMed ] [ Google Scholar ]
• Smith, J. D., Schneider, B. H., Smith, P. K., & Ananiadou, K. (2004). The effectiveness of whole‐school antibullying programs: A synthesis of evaluation research . School psychology review , 33 , 547–560. [ Google Scholar ]
• Smith, P. K., Kwak, K., & Toda, Y. (2016). School bullying in different cultures: Eastern and Western perspectives . Cambridge University Press. [ Google Scholar ]
• Solberg, M. E., & Olweus, D. (2003). Prevalence estimation of school bullying with the Olweus Bully/Victim Questionnaire . Aggressive Behavior , 29 ( 3 ), 239–268. [ Google Scholar ]
• Steinmaus, C., Smith, A. H., Jones, R. M., & Smith, M. T. (2008). Meta‐analysis of benzene exposure and non‐Hodgkin lymphoma: Biases could mask an important association . Occupational & Environmental Medicine , 65 ( 6 ), 371–378. 10.1136/oem.2007.036913 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Strøm, I. F., Thoresen, S., Wentzel‐Larsen, T., & Dyb, G. (2013). Violence, bullying and academic achievement: A study of 15‐year‐old adolescents and their school environment . Child Abuse & Neglect , 37 ( 4 ), 243–251. 10.1016/j.chiabu.2012.10.010 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Swearer, S. M., & Espelage, D. L. (2011). A social‐ecological framework of bullying among youth. Bullying in North American schools . Routledge. [ Google Scholar ]
• Swearer, S., Siebecker, A. B., Johnsen‐Frerichs, L. A., & Wang, C. (2010). Assessment of bullying/victimization: The problem of comparability across studies and methodologies. In Jimerson S. R., Swearer S. M. & Espelage D. L. (Eds.), Handbook of bullying in schools: An international perspective (pp. 305–327). Routledge. [ Google Scholar ]
• Tajfel, H., & Turner, J. (1979). An integrative theory of intergroup conflict. In Austin W. G. & Worschel S. (Eds.), The social psychology of intergroup relations . Brooks/Cole Publishing. [ Google Scholar ]
• Trip, S., & Bora, C. (2010). Educatie rational‐emotiva si comportamentala. Program de preventive primara si secundara pentru clasele V‐VIII [Rational‐emotive and behavioral education. Primary and secondary prevention program for V‐VIII grades]/Oradea, Romania: Editura Universitati din Oradea.
• Tsiantis, J. (Ed.). (2011). Bullying prevention and coping workshops: Class activities with students . A.P.H.C.A. [ Google Scholar ]
• Ttofi, M. M. (2015). Adolescent bullying linked to depression in early adulthood: Evidence supports early intervention . British Medical Journal , 350 , h2694. [ PubMed ] [ Google Scholar ]
• Ttofi, M. M., & Farrington, D. P. (2011). Effectiveness of school‐based programs to reduce bullying: A systematic and meta‐analytic review . Journal of Experimental Criminology , 7 , 27–56. [ Google Scholar ]
• Ttofi, M. M., Farrington, D. P., Lösel, F., & Loeber, R. (2011a). Do victims of school bullies tend to become depressed later in life? A systematic review and meta‐analysis of longitudinal studies . Journal of Aggression, Conflict and Peace Research , 3 ( 2 ), 63–73. [ Google Scholar ]
• Ttofi, M. M., Farrington, D. P., Lösel, F., & Loeber, R. (2011b). The predictive efficiency of school bullying versus later offending: A systematic/meta‐analytic review of longitudinal studies . Criminal Behaviour and Mental Health , 21 , 80–89. [ PubMed ] [ Google Scholar ]
• Ttofi, M. M., Farrington, D. P., & Lösel, F. (2012). School bullying as a predictor of violence later in life: A systematic review and meta‐analysis of prospective longitudinal studies . Aggression and Violent Behaviour , 17 , 405–418. [ Google Scholar ]
• Ttofi, M. M., Eisner, M., & Bradshaw, C. P. (2014). Bullying prevention: Assessing existing meta‐evaluations. In Bruinsma G. & Weisburd D. (Eds.), Encyclopaedia of criminology and criminal justice (pp. 231–242). Springer. [ Google Scholar ]
• Ttofi, M. M., Farrington, D. P., Lösel, F., Crago, R. V., & Theodorakis, N. (2016). School bullying and drug use later in life: A meta‐analytic investigation . School Pscyhology Quarterly , 31 ( 1 ), 8–27. [ PubMed ] [ Google Scholar ]
• Valdebenito, S., Eisner, M., Farrington, D. P., Ttofi, M. M., & Sutherland, A. (2018). School‐based interventions for reducing disciplinary school exclusion: A systematic review . Campbell Systematic Reviews , 2018 , 1. 10.4073/csr.2018.1 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Valdebenito, S., Ttofi, M., & Eisner, M. (2015). Prevalence rates of drug use among school bullies and victims: A systematic review and meta‐analysis of cross‐sectional studies . Aggression and Violent Behavior , 23 , 137–146. 10.1016/j.avb.2015.05.004 [ CrossRef ] [ Google Scholar ]
• Valdebenito, S., Ttofi, M. M., Eisner, M., & Gaffney, H. (2018). Weapon carrying in and out of school among pure bullies, pure victims and bully‐victims: A systematic review and meta‐analysis of cross‐sectional and longitudinal studies . Aggression and Violent Behavior , 33 , 62–77. [ Google Scholar ]
• Volk, A. A., Veenstra, R., & Espelage, D. L. (2017). So you want to study bullying? Recommendations to enhance the validity, transparency, and comparability of bullying research . Aggression and Violent Behavior , 36 , 34–43. [ Google Scholar ]
• Vreeman, R. C., & Carroll, A. E. (2007). A systematic review of school‐based interventions to prevent bullying . Archives of Pediatrics and Adolescent Medicine , 161 , 78–88. [ PubMed ] [ Google Scholar ]
• Weisburd, D. (2003). Ethical practice and evaluation of interventions in crime and justice: The moral imperative for randomized trials . Evaluation Review , 27 ( 3 ), 336–354. 10.1177/0193841X03027003007 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Weisburd, D., Lum, C. M., & Petrosino, A. (2001). Does research design affect study outcomes in criminal justice? ANNALS of the American Academy of Political and Social Science , 578 ( 1 ), 50–70. 10.1177/000271620157800104 [ CrossRef ] [ Google Scholar ]
• Wilson, D. B. (2010). Meta‐analysis. In Piquero A. R. & Weisburd D. (Eds.), Handbook of quantitative criminology (pp. 181–208). Springer. [ Google Scholar ]
• Woolf‐King, S. E., Steinmaus, C. M., Reingold, A. L., & Hahn, J. A. (2013). An update on alcohol use and risk of HIV infection in sub‐Saharan Africa: Meta‐analysis and future research directions . International Journal of Alcohol and Drug Research , 2 ( 1 ), 99–110. [ Google Scholar ]
• Zych, I., Baldry, A. C., Farrington, D. P., & Llorent, V. J. (2019). Are children involved in cyberbullying low on empathy? A systematic review and meta‐analysis of research on empathy versus different cyberbullying roles . Aggression and Violent Behavior , 45 , 83–97. 10.1016/j.avb.2018.03.004 [ CrossRef ] [ Google Scholar ]
• Zych, I., Farrington, D. P., Llorent, V. J., & Ttofi, M. M. (2017). Protecting children against bullying and its consequences: SpringerBriefs in behavioral criminology . Springer International Publishing. 10.1007/978-3-319-53028-4 [ CrossRef ] [ Google Scholar ]
• Zych, I., Ortega‐Ruiz, R., & del Rey, R. (2015). Systematic review of theoretical studies on bullying and cyberbullying: Facts, knowledge, prevention, and intervention . Aggression and Violent Behavior , 23 , 1–21. 10.1016/j.avb.2015.10.001 [ CrossRef ] [ Google Scholar ]
• Zych, I., Viejo, C., Vila, E., & Farrington, D. P. (2019). School bullying and dating violence in adolescents: A systematic review and meta‐analysis . Trauma, Violence, & Abuse , 152483801985446. [ PubMed ] [ Google Scholar ]