reliable source for literature review

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Chapter 5: The Literature Review

5.3 Acceptable sources for literature reviews

Following are a few acceptable sources for literature reviews, listed in order from what will be considered most acceptable to less acceptable sources for your literature review assignments:

• Peer reviewed journal articles.
• Edited academic books.
• Articles in professional journals.
• Statistical data from government websites.
• Website material from professional associations (use sparingly and carefully). The following sections will explain and provide examples of these various sources.

Peer reviewed journal articles (papers)

A peer reviewed journal article is a paper that has been submitted to a scholarly journal, accepted, and published. Peer review journal papers go through a rigorous, blind review process of peer review. What this means is that two to three experts in the area of research featured in the paper have reviewed and accepted the paper for publication. The names of the author(s) who are seeking to publish the research have been removed (blind review), so as to minimize any bias towards the authors of the research (albeit, sometimes a savvy reviewer can discern who has done the research based upon previous publications, etc.). This blind review process can be long (often 12 to 18 months) and may involve many back and forth edits on the behalf of the researchers, as they work to address the edits and concerns of the peers who reviewed their paper. Often, reviewers will reject the paper for a variety of reasons, such as unclear or questionable methods, lack of contribution to the field, etc. Because peer reviewed journal articles have gone through a rigorous process of review, they are considered to be the premier source for research. Peer reviewed journal articles should serve as the foundation for your literature review.

The following link will provide more information on peer reviewed journal articles. Make sure you watch the little video on the upper left-hand side of your screen, in addition to reading the material at the following website:    http://guides.lib.jjay.cuny.edu/c.php?g=288333&p=1922599

Edited academic books

An edited academic book is a collection of scholarly scientific papers written by different authors. The works are original papers, not published elsewhere (“Edited volume,” 2018). The papers within the text also go through a process of review; however, the review is often not a blind review because the authors have been invited to contribute to the book. Consequently, edited academic books are fine to use for your literature review, but you also want to ensure that your literature review contains mostly peer reviewed journal papers.

Articles in professional journals

Articles from professional journals should be used with caution for your literature review. This is because articles in trade journals are not usually peer reviewed, even though they may appear to be. A good way to find out is to read the “About Us” section of the professional journal, which should state whether or not the papers are peer reviewed. You can also find out by Googling the name of the journal and adding “peer reviewed” to the search.

Statistical data from governmental websites

Governmental websites can be excellent sources for statistical data, e.g, Statistics Canada collects and publishes data related to the economy, society, and the environment (see https://www.statcan.gc.ca/eng/start ).

Website material from professional associations

Material from other websites can also serve as a source for statistics that you may need for your literature review. Since you want to justify the value of the research that interests you, you might make use of a professional association’s website to learn how many members they have, for example. You might want to demonstrate, as part of the introduction to your literature review, why more research on the topic of PTSD in police officers is important. You could use peer reviewed journal articles to determine the prevalence of PTSD in police officers in Canada in the last ten years, and then use the Ontario Police Officers´ Association website to determine the approximate number of police officers employed in the Province of Ontario over the last ten years. This might help you estimate how many police officers could be suffering with PTSD in Ontario. That number could potentially help to justify a research grant down the road. But again, this type of website- based material should be used with caution and sparingly.

Research Methods for the Social Sciences: An Introduction Copyright © 2020 by Valerie Sheppard is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

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Writing a Literature Review

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A literature review is a document or section of a document that collects key sources on a topic and discusses those sources in conversation with each other (also called synthesis ). The lit review is an important genre in many disciplines, not just literature (i.e., the study of works of literature such as novels and plays). When we say “literature review” or refer to “the literature,” we are talking about the research ( scholarship ) in a given field. You will often see the terms “the research,” “the scholarship,” and “the literature” used mostly interchangeably.

Where, when, and why would I write a lit review?

There are a number of different situations where you might write a literature review, each with slightly different expectations; different disciplines, too, have field-specific expectations for what a literature review is and does. For instance, in the humanities, authors might include more overt argumentation and interpretation of source material in their literature reviews, whereas in the sciences, authors are more likely to report study designs and results in their literature reviews; these differences reflect these disciplines’ purposes and conventions in scholarship. You should always look at examples from your own discipline and talk to professors or mentors in your field to be sure you understand your discipline’s conventions, for literature reviews as well as for any other genre.

A literature review can be a part of a research paper or scholarly article, usually falling after the introduction and before the research methods sections. In these cases, the lit review just needs to cover scholarship that is important to the issue you are writing about; sometimes it will also cover key sources that informed your research methodology.

Lit reviews can also be standalone pieces, either as assignments in a class or as publications. In a class, a lit review may be assigned to help students familiarize themselves with a topic and with scholarship in their field, get an idea of the other researchers working on the topic they’re interested in, find gaps in existing research in order to propose new projects, and/or develop a theoretical framework and methodology for later research. As a publication, a lit review usually is meant to help make other scholars’ lives easier by collecting and summarizing, synthesizing, and analyzing existing research on a topic. This can be especially helpful for students or scholars getting into a new research area, or for directing an entire community of scholars toward questions that have not yet been answered.

What are the parts of a lit review?

Most lit reviews use a basic introduction-body-conclusion structure; if your lit review is part of a larger paper, the introduction and conclusion pieces may be just a few sentences while you focus most of your attention on the body. If your lit review is a standalone piece, the introduction and conclusion take up more space and give you a place to discuss your goals, research methods, and conclusions separately from where you discuss the literature itself.

Introduction:

• An introductory paragraph that explains what your working topic and thesis is
• A forecast of key topics or texts that will appear in the review
• Potentially, a description of how you found sources and how you analyzed them for inclusion and discussion in the review (more often found in published, standalone literature reviews than in lit review sections in an article or research paper)
• Summarize and synthesize: Give an overview of the main points of each source and combine them into a coherent whole
• Analyze and interpret: Don’t just paraphrase other researchers – add your own interpretations where possible, discussing the significance of findings in relation to the literature as a whole
• Critically Evaluate: Mention the strengths and weaknesses of your sources
• Write in well-structured paragraphs: Use transition words and topic sentence to draw connections, comparisons, and contrasts.

Conclusion:

• Summarize the key findings you have taken from the literature and emphasize their significance
• Connect it back to your primary research question

How should I organize my lit review?

Lit reviews can take many different organizational patterns depending on what you are trying to accomplish with the review. Here are some examples:

• Chronological : The simplest approach is to trace the development of the topic over time, which helps familiarize the audience with the topic (for instance if you are introducing something that is not commonly known in your field). If you choose this strategy, be careful to avoid simply listing and summarizing sources in order. Try to analyze the patterns, turning points, and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred (as mentioned previously, this may not be appropriate in your discipline — check with a teacher or mentor if you’re unsure).
• Thematic : If you have found some recurring central themes that you will continue working with throughout your piece, you can organize your literature review into subsections that address different aspects of the topic. For example, if you are reviewing literature about women and religion, key themes can include the role of women in churches and the religious attitude towards women.
• Qualitative versus quantitative research
• Empirical versus theoretical scholarship
• Divide the research by sociological, historical, or cultural sources
• Theoretical : In many humanities articles, the literature review is the foundation for the theoretical framework. You can use it to discuss various theories, models, and definitions of key concepts. You can argue for the relevance of a specific theoretical approach or combine various theorical concepts to create a framework for your research.

What are some strategies or tips I can use while writing my lit review?

Any lit review is only as good as the research it discusses; make sure your sources are well-chosen and your research is thorough. Don’t be afraid to do more research if you discover a new thread as you’re writing. More info on the research process is available in our "Conducting Research" resources .

As you’re doing your research, create an annotated bibliography ( see our page on the this type of document ). Much of the information used in an annotated bibliography can be used also in a literature review, so you’ll be not only partially drafting your lit review as you research, but also developing your sense of the larger conversation going on among scholars, professionals, and any other stakeholders in your topic.

Usually you will need to synthesize research rather than just summarizing it. This means drawing connections between sources to create a picture of the scholarly conversation on a topic over time. Many student writers struggle to synthesize because they feel they don’t have anything to add to the scholars they are citing; here are some strategies to help you:

• It often helps to remember that the point of these kinds of syntheses is to show your readers how you understand your research, to help them read the rest of your paper.
• Writing teachers often say synthesis is like hosting a dinner party: imagine all your sources are together in a room, discussing your topic. What are they saying to each other?
• Look at the in-text citations in each paragraph. Are you citing just one source for each paragraph? This usually indicates summary only. When you have multiple sources cited in a paragraph, you are more likely to be synthesizing them (not always, but often
• Read more about synthesis here.

The most interesting literature reviews are often written as arguments (again, as mentioned at the beginning of the page, this is discipline-specific and doesn’t work for all situations). Often, the literature review is where you can establish your research as filling a particular gap or as relevant in a particular way. You have some chance to do this in your introduction in an article, but the literature review section gives a more extended opportunity to establish the conversation in the way you would like your readers to see it. You can choose the intellectual lineage you would like to be part of and whose definitions matter most to your thinking (mostly humanities-specific, but this goes for sciences as well). In addressing these points, you argue for your place in the conversation, which tends to make the lit review more compelling than a simple reporting of other sources.

How To Find A-Grade Literature For Review

Sourcing, evaluating and organising.

By: David Phair (PhD) and Peter Quella (PhD) | January 2022

As we’ve discussed previously on our blog and YouTube channel, the first step of the literature review process is to source high-quality , relevant resources for your review, and to catalogue these pieces of literature in a systematic way so that you can digest and synthesise all the content efficiently.

In this article, we’ll look discuss 6 important things to keep in mind for the initial stage of your literature review so that you can source high-quality, relevant resources, quickly and efficiently. Let’s get started!

Overview: Literature Review Sourcing

• Develop and follow a clear literature search strategy
• Understand and use different types of literature correctly
• Carefully evaluate the quality of your potential sources
• Use a reference manager and a literature catalogue
• Read as broadly and comprehensively as possible
• Keep your golden thread front of mind throughout the process

1. Have a clear literature search strategy

As with any task in the research process, you need to have a clear plan of action before you get started, or you’ll end up wasting a lot of time and energy. So, before you begin your literature review , it’s useful to develop a simple search strategy . Broadly speaking, a good literature search strategy should include the following steps:

Step one – Clearly identify your golden thread

Your golden thread consists of your research aims , research objectives and research questions . These three components should be tightly aligned to form the focus of your research. If you’re unclear what your research aims and research questions are, you’re not going to have a clear direction when trying to source literature. As a result, you’re going to waste a lot of time reviewing irrelevant resources.

So, make sure that you have clarity regarding your golden thread before you start searching for literature. Of course, your research aims, objectives and questions may evolve or shift as a result of the literature review process (in fact, this is quite common), but you still need to have a clear focus to get things started.

Step two – Develop a keyword/keyphrase list

Once you’ve clearly articulated your golden thread in terms of the research aims, objectives and questions, the next step is to develop a list of keywords or keyphrases, based on these three elements (the golden thread). You’ll also want to include synonyms and alternative spellings (for example, American vs British English) in your list.

For example, if your research aims and research questions involve investigating organisational trust , your keyword list might include:

• Organisational trust
• Organizational trust (US spelling)
• Consumer trust
• Brand trust
• Online trust

When it comes to brainstorming keywords, the more the better . Don’t hold back at this stage. You’ll quickly find out which ones are useful, and which aren’t when you start searching. So, it’s best to just go as broad as possible here to ensure you cast a wide net.

Step three – Identify the relevant databases

Now that you’ve got a comprehensive set of keywords, the next step is to identify which literature databases will be most useful and relevant for your particular study. There are hundreds, if not thousands of databases out there, and they are often subject or discipline-specific . For example, within the medicine space, Medline is a popular one.

To identify relevant databases, it’s best to speak to your research advisor/supervisor, Grad Coach or a librarian at your university library. Oftentimes, a quick chat with a skilled librarian can yield tremendous insight. Don’t be shy to ask – chances are, they’ll be thrilled that you asked!

At this stage, you might be asking, “why not just use Google Scholar?”. Of course, an academic search engine like Google Scholar will be useful in terms of getting started and finding a broad range of resources, but it won’t always present every possible resource  or the best quality resources. It also has limited filtering options compared to some of the specialist databases, so you shouldn’t rely purely on Google Scholar.

Step four – Use Boolean operators to refine your search

Once you’ve identified your keywords and databases, it’s time to start searching for literature – hooray! However, you’ll quickly find that there is a seemingly endless number of journal articles to sift through, and you have limited time to work through the literature. So, you’ll need to get smart about how you use these databases – enter Boolean operators.

Boolean operators are special characters that allow you to refine your search. Common operators include:

• AND – only show results that contain both X and Y
• OR – show results that contain X or Y
• NOT – show results that include X, but not Y

These operators are incredibly useful, especially when there are topics that are very similar to yours but are not relevant . For example, if you’re researching something about the growth of apples, you’ll want to exclude all literature related to Apple, the company. Boolean operators allow you to cut out the irrelevant content and improve the signal to noise ratio in your search.

Need a helping hand?

2. Use different types of literature correctly

Once you start searching for literature, you’ll quickly notice that there are different “types” of resources that come up. It’s important to understand the different types of literature available to you and how to use each of them appropriately.

Generally speaking, you’ll find three categories of literature:

Primary literature

Secondary literature

Tertiary literature

Primary literature refers to journal articles , typically peer reviewed, which document a study that was undertaken, where data were collected and analysed, and findings were discussed. For example, a journal article that involves the collection and analysis of survey data to identify differences in personality between two groups of people.

Primary literature should, ideally, form the foundation of your literature review – the bread and butter, so to speak. You’ll likely refer to many of the arguments made and findings identified in these types of articles to build your own arguments throughout your literature review. You’ll also rely on these types of articles for theoretical models and frameworks, which may form the foundation of your own proposed framework, depending on the nature of your research.

Lastly, primary literature can be a useful source of measurement scales for quantitative studies. For example, many journal articles will include a copy of the survey measures they used at the end of the article, which will typically be reliable and valid. You can either use these “as is” or as a foundation for your own survey measures .

So, long story short, you’ll need a good stockpile of these types of resources. They are, admittedly, more “dense” and challenging to digest than the other types of literature, but taking the time to work through them will pay off greatly.

Secondary literature refers to journal articles that summarise and integrate the findings from primary literature. For example, you’ll likely find “review of the literature” type journal articles which provide an overview of the current state of the research (at the time of publication, of course).

Secondary literature is very useful for orienting yourself with regards to the current state of knowledge and identifying key researchers , seminal works and so on. In other words, they’re a good tool to make sure you’ve got a broad, comprehensive view of what all is out there. They’re not going to give you the level of detail that primary literature will (and they’ll likely be a bit outdated), but they’ll point you in the right direction.

In practical terms, it’s a good idea to start by reviewing secondary literature-type articles to help you get a bird’s eye view of the landscape and then dive deeper into the primary literature to get a grasp of the specifics and to bring your knowledge up to date with the most current studies.

The final category of literature refers to sources that would be considered less academic and scientifically rigorous in nature, but up to date and highly relevant. For example, sources such as current industry and country reports published by management consulting groups, news articles, blog posts and so on.

While these sources are not as credible and trustworthy as journal articles (especially peer-reviewed ones), they can provide very up to date information , whereas academic research tends to roll out quite slowly. Therefore, they can be very useful for contextualising your research topic and/or demonstrating a current trend. Quite often, you’d cite these types of sources in your introduction chapter rather than your literature review chapter, but you may still have use for them in the latter.

In summary, it’s important to understand the three different types of literature – primary, secondary and tertiary, and use them appropriately in your dissertation, thesis or research project.

3. Carefully evaluate the quality of your sources

As we’ve alluded to, not all literature is created equally. Not only does literature vary in terms of type (i.e., primary vs secondary), it also varies in terms of overall quality .

Simply put, all sources exist on a quality spectrum . On the high end of the spectrum are peer-reviewed articles published in popular, credible journals. Next are journal articles that are not peer-reviewed, or that are published in lower quality or lesser-known journals. In the middle are sources like textbooks and reports by professional organisations (e.g., management consulting firms). On the low end are sources like newspapers, blog posts and social media posts.

As you can probably see, this loosely reflects the categories we mentioned previously (primary, secondary and tertiary literature), so there is once again a trade-off between quality and recency . Therefore, you need to carefully evaluate the quality of each potential source and let this inform how you use it in your literature review. Importantly, this doesn’t mean that you can’t include a newspaper article or blog post as a source – it just means that you shouldn’t rely too heavily on these types of courses as the core of your argument.

When evaluating journal articles, you can consider their citation count (i.e., the number of other articles that reference them) as a quality indicator. But keep in mind that citation count is a product of many factors , including the popularity of the article, the popularity of the research field and most importantly, time. In other words, it’s natural for newer articles to have lower citation counts. This is useful to keep in mind, as you ideally want to focus on more recent literature (published within the last 3-5 years) in your literature review.

In summary, aim to focus on higher-quality literature , especially when you’re building core arguments in your literature review. You don’t, for example, want to make an argument regarding the importance and novelty of your research (i.e., its justification) based on some blogger’s opinion.

4. Use a reference manager and literature catalogue

As you review the literature and build your collection of potential sources, you’ll need a way to stay on top of all the details. To this end, it’s essential that you make use of both a reference manager and a literature catalogue . Let’s take a look at each of these.

The reference manager

Reference management software helps you store the reference information for each of your articles and manages the citation and reference list building task as you write up your actual literature review chapter. In other words, a reference manager ensures that your citations and reference list are correctly formatted in the reference style required by your university – e.g., Harvard, APA , MLA, etc.

Using a reference manager saves you the hassle of trying to manually type out your in-text citations and reference list, which you’re bound to mess up in some way. A simple comma out of place, incorrect italicisation or boldfacing can result in you losing marks, and that’s highly likely when you’re dealing with a large number of references. So, it just makes sense to use a piece of software for this task.

The good news is that there are loads of options , many of which are free . For new researchers, we usually recommend Mendeley or Zotero . So, don’t waste your time trying to manage your references manually – get yourself a reference manager ASAP.

The literature catalogue

The second tool you’ll need is a literature catalogue. This is simply an Excel document that you can easily compile yourself (or download our free one here ), where you list and categorise all your literature. You might doubt whether it’s really necessary to have a separate catalogue when you’ve already logged your reference data in a reference manager, but trust us, you’re going to need it. It’s quite common that throughout the literature review process, you’ll review hundreds of articles , so it’s simply impossible that you’ll remember all the details.

What makes a literature catalogue extremely powerful is that you can store as much information as you want for each piece of literature that you include (whereas a reference manager only includes basic fields). Typically, you would include things like:

• Title of the article
• One-line summary of the research
• Key findings and takeaways
• Context (i.e. where did it take place)
• Useful quotes
• Methodology (e.g. qualitative, quantitative or mixed methods)
• Category (you can customise as many categories as makes sense for you)
• Quality of resource
• Type of literature (e.g. primary, secondary or tertiary)

These are just some examples – ultimately you need to customise your catalogue to suit your needs. But, as you can see, the more detailed you get, the more useful your catalogue will become when it’s time to synthesise the research and write up your literature. For example, you could quickly filter the catalogue to display all papers that support a certain hypothesis, that argue in a specific direction, or that were written at a certain time.

5. Read widely (and efficiently)

As we’ve discussed in other posts , the purpose of the literature review chapter is to present and synthesise the current state of knowledge in relation to your research aims, objectives and research questions. To do this, you’ll need to read as broadly and comprehensively as possible. You’ll need to demonstrate to your marker that you “know your stuff” and have a strong understanding of the relevant literature.

Ideally, your literature review should include an eclectic mix of research that features multiple perspectives . In other words, you need to avoid getting tunnel vision and running down one narrow stream of literature. Ideally, you want to highlight both the agreements and disagreements in the literature to show that you’ve got a well-balanced view of the situation.

If your topic is particularly novel and there isn’t a lot of literature available, you can focus your efforts on adjacent literature . For example, if you’re researching factors that cultivate organisational trust in Germany, but there’s very little literature on this, you can draw on US and UK-based studies to form your theoretical foundation. Similarly, if you’re investigating an occurrence in an under-researched industry, you can look at other industries for literature.

As you read each journal article, be sure to scan the reference list for further reading (this technique is called “snowballing”). By doing this, you will quickly identify key literature within a topic area and fast-track your literature review process. You can also check which articles have cited any given article using Google Scholar, which will give you a “forward view” in terms of the progress of the literature.

Given that you’ll need to work through a large amount of literature, it’s useful to adopt a “strategic skimming ” approach when you’re initially assessing articles, so that you don’t need to read the entire journal article . In practical terms, this means you can focus on just the title and abstract at first, and if the article seems relevant based on those, you can jump to the findings section and limitations section . These sections will give you a solid indicator as to whether the resource is relevant to your study, which you can then shortlist for full reading.

6. Keep your golden thread front of mind

Your golden thread (i.e., your research aims, objectives and research questions) needs to guide every decision you make throughout your dissertation, thesis, or research project. This is especially true in the literature review stage, as the golden thread should act as a litmus test for relevance whenever you’re reviewing potential articles or resources. In other words, if an article doesn’t relate to your golden thread, its probably not worth spending time on.

Keep in mind that your research aims, objectives and research questions may evolve as a result of the literature review process. For example, you may find that after reviewing the literature in more depth, your topic focus is not as novel as you originally thought, or that there’s an adjacent area that is more deserving of investigation. This is perfectly natural, so don’t be surprised if your focus shifts somewhat during the review process. Just remember to update your literature review in this case and be sure to update any previous chapters so that your document has a consistent focus throughout.

Wrapping up

In this article, we covered 6 pointers to help you find and evaluate high-quality resources for your literature review. To recap:

• Understand and use different types of literature for the right purpose

If you have any questions, please feel free to leave a comment . Alternatively, if you’d like hands-on help with your literature review, be sure to check out our 1-on-1 private coaching services here.

Psst… there’s more!

This post is an extract from our bestselling short course, Literature Review Bootcamp . If you want to work smart, you don't want to miss this .

this is very helpful to any researcher, I am learning this for the benefit of myself and overs as a library staff

Of course this is useful to most of researchers. I have learnt a lot issues which are relevant to teaching research. Surely they will enjoy my research sessions.

Thank you. Very clear and concise

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Literature Review - what is a Literature Review, why it is important and how it is done

• Strategies to Find Sources

Evaluating Literature Reviews and Sources

Reading critically, tips to evaluate sources.

• Tips for Writing Literature Reviews
• Writing Literature Review: Useful Sites
• Citation Resources
• Other Academic Writings
• Useful Resources

A good literature review evaluates a wide variety of sources (academic articles, scholarly books, government/NGO reports). It also evaluates literature reviews that study similar topics. This page offers you a list of resources and tips on how to evaluate the sources that you may use to write your review.

• A Closer Look at Evaluating Literature Reviews Excerpt from the book chapter, “Evaluating Introductions and Literature Reviews” in Fred Pyrczak’s Evaluating Research in Academic Journals: A Practical Guide to Realistic Evaluation , (Chapter 4 and 5). This PDF discusses and offers great advice on how to evaluate "Introductions" and "Literature Reviews" by listing questions and tips. First part focus on Introductions and in page 10 in the PDF, 37 in the text, it focus on "literature reviews".
• Tips for Evaluating Sources (Print vs. Internet Sources) Excellent page that will guide you on what to ask to determine if your source is a reliable one. Check the other topics in the guide: Evaluating Bibliographic Citations and Evaluation During Reading on the left side menu.

To be able to write a good Literature Review, you need to be able to read critically. Below are some tips that will help you evaluate the sources for your paper.

Reading critically (summary from How to Read Academic Texts Critically)

• Who is the author? What is his/her standing in the field.
• What is the author’s purpose? To offer advice, make practical suggestions, solve a specific problem, to critique or clarify?
• Note the experts in the field: are there specific names/labs that are frequently cited?
• Pay attention to methodology: is it sound? what testing procedures, subjects, materials were used?
• Note conflicting theories, methodologies and results. Are there any assumptions being made by most/some researchers?
• Theories: have they evolved overtime?
• Evaluate and synthesize the findings and conclusions. How does this study contribute to your project?

Useful links:

• How to Read a Paper (University of Waterloo, Canada) This is an excellent paper that teach you how to read an academic paper, how to determine if it is something to set aside, or something to read deeply. Good advice to organize your literature for the Literature Review or just reading for classes.

Criteria to evaluate sources:

• Authority : Who is the author? what is his/her credentials--what university he/she is affliliated? Is his/her area of expertise?
• Usefulness : How this source related to your topic? How current or relevant it is to your topic?
• Reliability : Does the information comes from a reliable, trusted source such as an academic journal?

Useful site - Critically Analyzing Information Sources (Cornell University Library)

• << Previous: Strategies to Find Sources
• Next: Tips for Writing Literature Reviews >>
• Last Updated: Jul 3, 2024 10:56 AM
• URL: https://lit.libguides.com/Literature-Review

The Library, Technological University of the Shannon: Midwest

Literature review sources

Sources for literature review can be divided into three categories as illustrated in table below. In your dissertation you will need to use all three categories of literature review sources:

Sources for literature review and examples

Generally, your literature review should integrate a wide range of sources such as:

• Books . Textbooks remain as the most important source to find models and theories related to the research area. Research the most respected authorities in your selected research area and find the latest editions of books authored by them. For example, in the area of marketing the most notable authors include Philip Kotler, Seth Godin, Malcolm Gladwell, Emanuel Rosen and others.
• Magazines . Industry-specific magazines are usually rich in scholarly articles and they can be effective source to learn about the latest trends and developments in the research area. Reading industry magazines can be the most enjoyable part of the literature review, assuming that your selected research area represents an area of your personal and professional interests, which should be the case anyways.
• Newspapers can be referred to as the main source of up-to-date news about the latest events related to the research area. However, the proportion of the use of newspapers in literature review is recommended to be less compared to alternative sources of secondary data such as books and magazines. This is due to the fact that newspaper articles mainly lack depth of analyses and discussions.
• Online articles . You can find online versions of all of the above sources. However, note that the levels of reliability of online articles can be highly compromised depending on the source due to the high levels of ease with which articles can be published online. Opinions offered in a wide range of online discussion blogs cannot be usually used in literature review. Similarly, dissertation assessors are not keen to appreciate references to a wide range of blogs, unless articles in these blogs are authored by respected authorities in the research area.

Your secondary data sources may comprise certain amount of grey literature as well. The term grey literature refers to type of literature produced by government, academics, business and industry in print and electronic formats, which is not controlled by commercial publishers. It is called ‘grey’ because the status of the information in grey literature is not certain. In other words, any publication that has not been peer reviewed for publication is grey literature.

The necessity to use grey literature arises when there is no enough peer reviewed publications are available for the subject of your study.

John Dudovskiy

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• Research Guides

Organizing Your Social Sciences Research Paper

• 5. The Literature Review
• Purpose of Guide
• Design Flaws to Avoid
• Independent and Dependent Variables
• Glossary of Research Terms
• Reading Research Effectively
• Narrowing a Topic Idea
• Broadening a Topic Idea
• Extending the Timeliness of a Topic Idea
• Academic Writing Style
• Applying Critical Thinking
• Choosing a Title
• Making an Outline
• Paragraph Development
• Research Process Video Series
• Executive Summary
• The C.A.R.S. Model
• Background Information
• The Research Problem/Question
• Theoretical Framework
• Citation Tracking
• Content Alert Services
• Evaluating Sources
• Primary Sources
• Secondary Sources
• Tiertiary Sources
• Scholarly vs. Popular Publications
• Qualitative Methods
• Quantitative Methods
• Insiderness
• Using Non-Textual Elements
• Limitations of the Study
• Common Grammar Mistakes
• Writing Concisely
• Avoiding Plagiarism
• Footnotes or Endnotes?
• Further Readings
• Generative AI and Writing
• USC Libraries Tutorials and Other Guides
• Bibliography

A literature review surveys prior research published in books, scholarly articles, and any other sources relevant to a particular issue, area of research, or theory, and by so doing, provides a description, summary, and critical evaluation of these works in relation to the research problem being investigated. Literature reviews are designed to provide an overview of sources you have used in researching a particular topic and to demonstrate to your readers how your research fits within existing scholarship about the topic.

Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . Fourth edition. Thousand Oaks, CA: SAGE, 2014.

Importance of a Good Literature Review

A literature review may consist of simply a summary of key sources, but in the social sciences, a literature review usually has an organizational pattern and combines both summary and synthesis, often within specific conceptual categories . A summary is a recap of the important information of the source, but a synthesis is a re-organization, or a reshuffling, of that information in a way that informs how you are planning to investigate a research problem. The analytical features of a literature review might:

• Give a new interpretation of old material or combine new with old interpretations,
• Trace the intellectual progression of the field, including major debates,
• Depending on the situation, evaluate the sources and advise the reader on the most pertinent or relevant research, or
• Usually in the conclusion of a literature review, identify where gaps exist in how a problem has been researched to date.

Given this, the purpose of a literature review is to:

• Place each work in the context of its contribution to understanding the research problem being studied.
• Describe the relationship of each work to the others under consideration.
• Identify new ways to interpret prior research.
• Reveal any gaps that exist in the literature.
• Resolve conflicts amongst seemingly contradictory previous studies.
• Identify areas of prior scholarship to prevent duplication of effort.
• Point the way in fulfilling a need for additional research.
• Locate your own research within the context of existing literature [very important].

Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper. 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques . Los Angeles, CA: SAGE, 2011; Knopf, Jeffrey W. "Doing a Literature Review." PS: Political Science and Politics 39 (January 2006): 127-132; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students . 2nd ed. Los Angeles, CA: SAGE, 2012.

Types of Literature Reviews

It is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the primary studies. Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally among scholars that become part of the body of epistemological traditions within the field.

In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews. Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are a number of approaches you could adopt depending upon the type of analysis underpinning your study.

Argumentative Review This form examines literature selectively in order to support or refute an argument, deeply embedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to make summary claims of the sort found in systematic reviews [see below].

Integrative Review Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses or research problems. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication. This is the most common form of review in the social sciences.

Historical Review Few things rest in isolation from historical precedent. Historical literature reviews focus on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.

Methodological Review A review does not always focus on what someone said [findings], but how they came about saying what they say [method of analysis]. Reviewing methods of analysis provides a framework of understanding at different levels [i.e. those of theory, substantive fields, research approaches, and data collection and analysis techniques], how researchers draw upon a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection, and data analysis. This approach helps highlight ethical issues which you should be aware of and consider as you go through your own study.

Systematic Review This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyze data from the studies that are included in the review. The goal is to deliberately document, critically evaluate, and summarize scientifically all of the research about a clearly defined research problem . Typically it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?" This type of literature review is primarily applied to examining prior research studies in clinical medicine and allied health fields, but it is increasingly being used in the social sciences.

Theoretical Review The purpose of this form is to examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review helps to establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.

NOTE: Most often the literature review will incorporate some combination of types. For example, a review that examines literature supporting or refuting an argument, assumption, or philosophical problem related to the research problem will also need to include writing supported by sources that establish the history of these arguments in the literature.

Baumeister, Roy F. and Mark R. Leary. "Writing Narrative Literature Reviews."  Review of General Psychology 1 (September 1997): 311-320; Mark R. Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147; Petticrew, Mark and Helen Roberts. Systematic Reviews in the Social Sciences: A Practical Guide . Malden, MA: Blackwell Publishers, 2006; Torracro, Richard. "Writing Integrative Literature Reviews: Guidelines and Examples." Human Resource Development Review 4 (September 2005): 356-367; Rocco, Tonette S. and Maria S. Plakhotnik. "Literature Reviews, Conceptual Frameworks, and Theoretical Frameworks: Terms, Functions, and Distinctions." Human Ressource Development Review 8 (March 2008): 120-130; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016.

Structure and Writing Style

I.  Thinking About Your Literature Review

The structure of a literature review should include the following in support of understanding the research problem :

• An overview of the subject, issue, or theory under consideration, along with the objectives of the literature review,
• Division of works under review into themes or categories [e.g. works that support a particular position, those against, and those offering alternative approaches entirely],
• An explanation of how each work is similar to and how it varies from the others,
• Conclusions as to which pieces are best considered in their argument, are most convincing of their opinions, and make the greatest contribution to the understanding and development of their area of research.

The critical evaluation of each work should consider :

• Provenance -- what are the author's credentials? Are the author's arguments supported by evidence [e.g. primary historical material, case studies, narratives, statistics, recent scientific findings]?
• Methodology -- were the techniques used to identify, gather, and analyze the data appropriate to addressing the research problem? Was the sample size appropriate? Were the results effectively interpreted and reported?
• Objectivity -- is the author's perspective even-handed or prejudicial? Is contrary data considered or is certain pertinent information ignored to prove the author's point?
• Persuasiveness -- which of the author's theses are most convincing or least convincing?
• Validity -- are the author's arguments and conclusions convincing? Does the work ultimately contribute in any significant way to an understanding of the subject?

II.  Development of the Literature Review

Four Basic Stages of Writing 1.  Problem formulation -- which topic or field is being examined and what are its component issues? 2.  Literature search -- finding materials relevant to the subject being explored. 3.  Data evaluation -- determining which literature makes a significant contribution to the understanding of the topic. 4.  Analysis and interpretation -- discussing the findings and conclusions of pertinent literature.

Consider the following issues before writing the literature review: Clarify If your assignment is not specific about what form your literature review should take, seek clarification from your professor by asking these questions: 1.  Roughly how many sources would be appropriate to include? 2.  What types of sources should I review (books, journal articles, websites; scholarly versus popular sources)? 3.  Should I summarize, synthesize, or critique sources by discussing a common theme or issue? 4.  Should I evaluate the sources in any way beyond evaluating how they relate to understanding the research problem? 5.  Should I provide subheadings and other background information, such as definitions and/or a history? Find Models Use the exercise of reviewing the literature to examine how authors in your discipline or area of interest have composed their literature review sections. Read them to get a sense of the types of themes you might want to look for in your own research or to identify ways to organize your final review. The bibliography or reference section of sources you've already read, such as required readings in the course syllabus, are also excellent entry points into your own research. Narrow the Topic The narrower your topic, the easier it will be to limit the number of sources you need to read in order to obtain a good survey of relevant resources. Your professor will probably not expect you to read everything that's available about the topic, but you'll make the act of reviewing easier if you first limit scope of the research problem. A good strategy is to begin by searching the USC Libraries Catalog for recent books about the topic and review the table of contents for chapters that focuses on specific issues. You can also review the indexes of books to find references to specific issues that can serve as the focus of your research. For example, a book surveying the history of the Israeli-Palestinian conflict may include a chapter on the role Egypt has played in mediating the conflict, or look in the index for the pages where Egypt is mentioned in the text. Consider Whether Your Sources are Current Some disciplines require that you use information that is as current as possible. This is particularly true in disciplines in medicine and the sciences where research conducted becomes obsolete very quickly as new discoveries are made. However, when writing a review in the social sciences, a survey of the history of the literature may be required. In other words, a complete understanding the research problem requires you to deliberately examine how knowledge and perspectives have changed over time. Sort through other current bibliographies or literature reviews in the field to get a sense of what your discipline expects. You can also use this method to explore what is considered by scholars to be a "hot topic" and what is not.

III.  Ways to Organize Your Literature Review

Chronology of Events If your review follows the chronological method, you could write about the materials according to when they were published. This approach should only be followed if a clear path of research building on previous research can be identified and that these trends follow a clear chronological order of development. For example, a literature review that focuses on continuing research about the emergence of German economic power after the fall of the Soviet Union. By Publication Order your sources by publication chronology, then, only if the order demonstrates a more important trend. For instance, you could order a review of literature on environmental studies of brown fields if the progression revealed, for example, a change in the soil collection practices of the researchers who wrote and/or conducted the studies. Thematic [“conceptual categories”] A thematic literature review is the most common approach to summarizing prior research in the social and behavioral sciences. Thematic reviews are organized around a topic or issue, rather than the progression of time, although the progression of time may still be incorporated into a thematic review. For example, a review of the Internet’s impact on American presidential politics could focus on the development of online political satire. While the study focuses on one topic, the Internet’s impact on American presidential politics, it would still be organized chronologically reflecting technological developments in media. The difference in this example between a "chronological" and a "thematic" approach is what is emphasized the most: themes related to the role of the Internet in presidential politics. Note that more authentic thematic reviews tend to break away from chronological order. A review organized in this manner would shift between time periods within each section according to the point being made. Methodological A methodological approach focuses on the methods utilized by the researcher. For the Internet in American presidential politics project, one methodological approach would be to look at cultural differences between the portrayal of American presidents on American, British, and French websites. Or the review might focus on the fundraising impact of the Internet on a particular political party. A methodological scope will influence either the types of documents in the review or the way in which these documents are discussed.

Other Sections of Your Literature Review Once you've decided on the organizational method for your literature review, the sections you need to include in the paper should be easy to figure out because they arise from your organizational strategy. In other words, a chronological review would have subsections for each vital time period; a thematic review would have subtopics based upon factors that relate to the theme or issue. However, sometimes you may need to add additional sections that are necessary for your study, but do not fit in the organizational strategy of the body. What other sections you include in the body is up to you. However, only include what is necessary for the reader to locate your study within the larger scholarship about the research problem.

Here are examples of other sections, usually in the form of a single paragraph, you may need to include depending on the type of review you write:

• Current Situation : Information necessary to understand the current topic or focus of the literature review.
• Sources Used : Describes the methods and resources [e.g., databases] you used to identify the literature you reviewed.
• History : The chronological progression of the field, the research literature, or an idea that is necessary to understand the literature review, if the body of the literature review is not already a chronology.
• Selection Methods : Criteria you used to select (and perhaps exclude) sources in your literature review. For instance, you might explain that your review includes only peer-reviewed [i.e., scholarly] sources.
• Standards : Description of the way in which you present your information.
• Questions for Further Research : What questions about the field has the review sparked? How will you further your research as a result of the review?

IV.  Writing Your Literature Review

Once you've settled on how to organize your literature review, you're ready to write each section. When writing your review, keep in mind these issues.

Use Evidence A literature review section is, in this sense, just like any other academic research paper. Your interpretation of the available sources must be backed up with evidence [citations] that demonstrates that what you are saying is valid. Be Selective Select only the most important points in each source to highlight in the review. The type of information you choose to mention should relate directly to the research problem, whether it is thematic, methodological, or chronological. Related items that provide additional information, but that are not key to understanding the research problem, can be included in a list of further readings . Use Quotes Sparingly Some short quotes are appropriate if you want to emphasize a point, or if what an author stated cannot be easily paraphrased. Sometimes you may need to quote certain terminology that was coined by the author, is not common knowledge, or taken directly from the study. Do not use extensive quotes as a substitute for using your own words in reviewing the literature. Summarize and Synthesize Remember to summarize and synthesize your sources within each thematic paragraph as well as throughout the review. Recapitulate important features of a research study, but then synthesize it by rephrasing the study's significance and relating it to your own work and the work of others. Keep Your Own Voice While the literature review presents others' ideas, your voice [the writer's] should remain front and center. For example, weave references to other sources into what you are writing but maintain your own voice by starting and ending the paragraph with your own ideas and wording. Use Caution When Paraphrasing When paraphrasing a source that is not your own, be sure to represent the author's information or opinions accurately and in your own words. Even when paraphrasing an author’s work, you still must provide a citation to that work.

V.  Common Mistakes to Avoid

These are the most common mistakes made in reviewing social science research literature.

• Sources in your literature review do not clearly relate to the research problem;
• You do not take sufficient time to define and identify the most relevant sources to use in the literature review related to the research problem;
• Relies exclusively on secondary analytical sources rather than including relevant primary research studies or data;
• Uncritically accepts another researcher's findings and interpretations as valid, rather than examining critically all aspects of the research design and analysis;
• Does not describe the search procedures that were used in identifying the literature to review;
• Reports isolated statistical results rather than synthesizing them in chi-squared or meta-analytic methods; and,
• Only includes research that validates assumptions and does not consider contrary findings and alternative interpretations found in the literature.

Cook, Kathleen E. and Elise Murowchick. “Do Literature Review Skills Transfer from One Course to Another?” Psychology Learning and Teaching 13 (March 2014): 3-11; Fink, Arlene. Conducting Research Literature Reviews: From the Internet to Paper . 2nd ed. Thousand Oaks, CA: Sage, 2005; Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1998; Jesson, Jill. Doing Your Literature Review: Traditional and Systematic Techniques . London: SAGE, 2011; Literature Review Handout. Online Writing Center. Liberty University; Literature Reviews. The Writing Center. University of North Carolina; Onwuegbuzie, Anthony J. and Rebecca Frels. Seven Steps to a Comprehensive Literature Review: A Multimodal and Cultural Approach . Los Angeles, CA: SAGE, 2016; Ridley, Diana. The Literature Review: A Step-by-Step Guide for Students . 2nd ed. Los Angeles, CA: SAGE, 2012; Randolph, Justus J. “A Guide to Writing the Dissertation Literature Review." Practical Assessment, Research, and Evaluation. vol. 14, June 2009; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016; Taylor, Dena. The Literature Review: A Few Tips On Conducting It. University College Writing Centre. University of Toronto; Writing a Literature Review. Academic Skills Centre. University of Canberra.

Writing Tip

Break Out of Your Disciplinary Box!

Thinking interdisciplinarily about a research problem can be a rewarding exercise in applying new ideas, theories, or concepts to an old problem. For example, what might cultural anthropologists say about the continuing conflict in the Middle East? In what ways might geographers view the need for better distribution of social service agencies in large cities than how social workers might study the issue? You don’t want to substitute a thorough review of core research literature in your discipline for studies conducted in other fields of study. However, particularly in the social sciences, thinking about research problems from multiple vectors is a key strategy for finding new solutions to a problem or gaining a new perspective. Consult with a librarian about identifying research databases in other disciplines; almost every field of study has at least one comprehensive database devoted to indexing its research literature.

Frodeman, Robert. The Oxford Handbook of Interdisciplinarity . New York: Oxford University Press, 2010.

Another Writing Tip

Don't Just Review for Content!

While conducting a review of the literature, maximize the time you devote to writing this part of your paper by thinking broadly about what you should be looking for and evaluating. Review not just what scholars are saying, but how are they saying it. Some questions to ask:

• How are they organizing their ideas?
• What methods have they used to study the problem?
• What theories have been used to explain, predict, or understand their research problem?
• What sources have they cited to support their conclusions?
• How have they used non-textual elements [e.g., charts, graphs, figures, etc.] to illustrate key points?

When you begin to write your literature review section, you'll be glad you dug deeper into how the research was designed and constructed because it establishes a means for developing more substantial analysis and interpretation of the research problem.

Hart, Chris. Doing a Literature Review: Releasing the Social Science Research Imagination . Thousand Oaks, CA: Sage Publications, 1 998.

Yet Another Writing Tip

When Do I Know I Can Stop Looking and Move On?

Here are several strategies you can utilize to assess whether you've thoroughly reviewed the literature:

• Look for repeating patterns in the research findings . If the same thing is being said, just by different people, then this likely demonstrates that the research problem has hit a conceptual dead end. At this point consider: Does your study extend current research?  Does it forge a new path? Or, does is merely add more of the same thing being said?
• Look at sources the authors cite to in their work . If you begin to see the same researchers cited again and again, then this is often an indication that no new ideas have been generated to address the research problem.
• Search Google Scholar to identify who has subsequently cited leading scholars already identified in your literature review [see next sub-tab]. This is called citation tracking and there are a number of sources that can help you identify who has cited whom, particularly scholars from outside of your discipline. Here again, if the same authors are being cited again and again, this may indicate no new literature has been written on the topic.

Onwuegbuzie, Anthony J. and Rebecca Frels. Seven Steps to a Comprehensive Literature Review: A Multimodal and Cultural Approach . Los Angeles, CA: Sage, 2016; Sutton, Anthea. Systematic Approaches to a Successful Literature Review . Los Angeles, CA: Sage Publications, 2016.

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• Literature Review: The What, Why and How-to Guide
• Evaluating Sources & Lit. Reviews

Literature Review: The What, Why and How-to Guide — Evaluating Sources & Lit. Reviews

• Getting Started
• Introduction
• How to Pick a Topic
• Strategies to Find Sources
• Tips for Writing Literature Reviews
• Writing Literature Review: Useful Sites
• Citation Resources
• Other Academic Writings

Reading Critically

To be able to write a good literature review, you need to be able to read critically. Below are some tips that will help you evaluate the sources for your paper.

Reading critically (summary from How to Read Academic Texts Critically)

• Who is the author? What is his/her standing in the field?
• What is the author’s purpose? To offer advice, make practical suggestions, solve a specific problem, to critique, or clarify?
• Note the experts in the field. Are there specific names/labs that are frequently cited?
• Pay attention to methodology. Is it sound? What testing procedures, subjects, and materials were used?
• Note conflicting theories, methodologies and results. Are there any assumptions being made by most/some researchers?
• Theories: Have they evolved overtime?
• Evaluate and synthesize the findings and conclusions. How does this study contribute to your project?

Useful links:

Tips to Evaluate Sources

Criteria to evaluate sources:

Authority : Who is the author? what is his/her credentials--what university he/she is affliliated? Is his/her area of expertise?

Usefulness : How this source related to your topic? How current or relevant it is to your topic?

Reliability : Does the information comes from a reliable, trusted source such as an academic journal?

Useful sites

• Critically Analyzing Information Sources (Cornell University Library)

Evaluating Literature Reviews and Sources

A good literature review evaluates a wide variety of sources (academic articles, scholarly books, government/NGO reports). It also evaluates literature reviews that study similar topics. This page offers you a list of resources and tips on how to evaluate the sources that you may use to write your review.

• A Closer Look at Evaluating Literature Reviews Excerpt from the book chapter, “Evaluating Introductions and Literature Reviews” in Fred Pyrczak’s Evaluating Research in Academic Journals: A Practical Guide to Realistic Evaluation , (Chapter 4 and 5). This PDF discusses and offers great advice on how to evaluate "Introductions" and "Literature Reviews" by listing questions and tips.

• Tips for Evaluating Sources (Print vs. Internet Sources) Excellent page that will guide you on what to ask to determine if your source is a reliable one. Check the other topics in the guide: Evaluating Bibliographic Citations and Evaluation During Reading on the left side menu.
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• Last Updated: Sep 21, 2022 2:16 PM
• URL: https://guides.lib.uconn.edu/literaturereview

Conducting a Literature Review

• Getting Started
• Define your Research Question
• Finding Sources
• Evaluating Sources
• Organizing the Review
• Cite and Manage your Sources

Introduction

The process of evaluating sources can take place when you first encounter a source, when you're reading it over, and as you incorporate it into your project. In general, some level of evaluation should take place at all of these stages, with different goals for each. The last evaluation will be discussed in "Organizing the Review," but we'll go over the first two here.

The overall purpose of evaluating sources is to make sure that your review has the most relevant, accurate, and unbiased literature in the field, so that you can determine what has already been learned about your topic and where further research may be needed.

Additional Resources

• Evaluate Sources by Kansas State University Libraries
• How to Evaluate Any Source by Skyline College Library

Evaluating Sources During the Initial Search Process

When you first encounter a potential source, you'll want to know very quickly whether it is worth reading in detail and considering for your literature review. To avoid wasting time on unhelpful sources as much as possible, it's generally best to run each article, book, or other resource you find through a quick checklist, using information you can find by skimming through the summary and introduction.

The two most common forms of early source evaluation are the "Big 5 Criteria" and the "CRAAP Test." These cover the same most significant variables for evaluation, and which one to use comes down to preference.

Big 5 Criteria:

The most important criteria for evaluating a potential resource are:

• Currency : When the source was published
• Coverage/Relevance : How closely related the source is to your topic and research question
• Authority : Who wrote the source and whether they are likely to be credible on the subject
• Accuracy : Whether the information is accurate or not (this will be more heavily evaluated further on in the research process, but you should skim through quickly for any obviously inaccurate information as a means of disqualifying the source)
• Objectivity/Purpose : Whether or not the source presents a biased point of view or agenda

A good rule of thumb for  Currency  is that medical, scientific, and technology resources should be published within the last 5 years to prevent the information from being out-of-date; for less time-sensitive topics like history or the humanities, resources published within the last 5-10 years are often acceptable.

CRAAP Test:

A helpful mnemonic to remember the evaluation criteria, CRAAP is an acronym for:

Helpful questions for initial evaluation:

• When was this source published?
• Is this source relevant to your topic?
• What are the author or authors' qualifications?
• Is the resource scholarly/peer-reviewed?
• Are sources cited to support the author's claims?
• Does the website or journal the source comes from have a bias to their reporting?
• Do you notice biased or emotional language in the summary or introduction?
• Do you notice spelling or grammatical errors in a quick examination of the source?
• Writing a Research Paper: Evaluate Sources by Kansas State University

Evaluating Sources During the Reading Process

Once a resource has passed the initial evaluation, you are ready to begin reading through it to more carefully determine if it belongs in your project. In addition to the questions posed above, which are always relevant to evaluating sources, you should look at your potential sources of literature with an eye to the following questions:

1. Is there any bias visible in the work?

You already began this process in the previous step and hopefully eliminated the most obviously unreliable sources, but as you read it is always important to keep an eye out for potential blind spots the author might have based on their own perspective. Bias is not inherently disqualifying -- a biased article may still have accurate information -- but it is essential to know if a bias exists and be aware of how it might impact how the information was gathered, evaluated, or delivered.

Peer-reviewed sources tend to be less likely to have this risk, because multiple editors had to go through the resource looking for mistakes or biases. They need to meet a much higher academic threshold.

2. How was the research conducted? Are there any strengths or weaknesses in its methodology?

It is important to understand how the study in your source was administered; a significant part of the literature review will be about potential gaps in the current research, so you need to understand how the existing research was done.

3. How does the author justify their conclusions?

Either through the results of their own research or by citing external evidence, an article, book, or other type of resource should provide proof of its claims. In the initial research process you checked to make sure that there was evidence supporting the author's assertions; now it is time to take a look at that evidence and see if you find it compelling, or if you think it doesn't justify the conclusions drawn by the article.

4. What similarities do these articles share?

Grouping your literature review by categories based on subtopic, findings, or chronology can be an extremely helpful way to organize your work. Take notes while you're reading of common themes and results to make planning the review easier.

5. Where does this research differ from the other sources?

While very close to the previous question, this one emphasizes what unique information, methodology, or insights a particular source brings to the overall understanding of the topic. What  new  knowledge is being brought to the table by this source that would justify it appearing in your literature review?

6. Does this source leave any unanswered questions or opportunities for further research?

Most scholarly journal articles will include a section near the end of the article addressing limits of their study and opportunities for further research. Examine these closely and see where other sources you have fill in the gaps, and where perhaps additional research needs to be done to gain a more complete understanding of your topic.

As you go through this process, you might find yourself eliminating certain sources that no longer seem like they fit with your project's goals, or getting inspired to search for additional sources based on new information you've found. This is a normal part of the research process, and additional searching may be necessary to fill in any gaps left after evaluating the sources you already have.

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• Last Updated: Apr 12, 2024 10:37 AM
• URL: https://libraryservices.acphs.edu/lit_review

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• Working with sources
• Evaluating Sources | Methods & Examples

Evaluating Sources | Methods & Examples

Published on June 2, 2022 by Eoghan Ryan . Revised on May 31, 2023.

The sources you use are an important component of your research. It’s important to evaluate the sources you’re considering using, in order to:

• Ensure that they’re credible
• Determine whether they’re relevant to your topic
• Assess the quality of their arguments

Table of contents

Evaluating a source’s credibility, evaluating a source’s relevance, evaluating a source’s arguments, other interesting articles, frequently asked questions about evaluating sources.

Evaluating the credibility of a source is an important way of sifting out misinformation and determining whether you should use it in your research. Useful approaches include the CRAAP test and lateral reading .

One of the best ways to evaluate source credibility is the CRAAP test . This stands for:

• Currency: Does the source reflect recent research?
• Relevance: Is the source related to your research topic?
• Authority: Is it a respected publication? Is the author an expert in their field?
• Accuracy: Does the source support its arguments and conclusions with evidence?
• Purpose: What is the author’s intention?

How you evaluate a source using these criteria will depend on your subject and focus. It’s important to understand the types of sources and how you should use them in your field of research.

Lateral reading

Lateral reading is the act of evaluating the credibility of a source by comparing it to other sources. This allows you to:

• Verify evidence
• Contextualize information
• Find potential weaknesses

If a source is using methods or drawing conclusions that are incompatible with other research in its field, it may not be reliable.

Rather than taking these figures at face value, you decide to determine the accuracy of the source’s claims by cross-checking them with official statistics such as census reports and figures compiled by the Department of Homeland Security’s Office of Immigration Statistics.

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How you evaluate the relevance of a source will depend on your topic, and on where you are in the research process . Preliminary evaluation helps you to pick out relevant sources in your search, while in-depth evaluation allows you to understand how they’re related.

Preliminary evaluation

As you cannot possibly read every source related to your topic, you can use preliminary evaluation to determine which sources might be relevant. This is especially important when you’re surveying a large number of sources (e.g., in a literature review or systematic review ).

One way to do this is to look at paratextual material, or the parts of a work other than the text itself.

• Look at the table of contents to determine the scope of the work.
• Consult the index for key terms or the names of important scholars.

You can also read abstracts , prefaces , introductions , and conclusions . These will give you a clear idea of the author’s intentions, the parameters of the research, and even the conclusions they draw.

Preliminary evaluation is useful as it allows you to:

• Determine whether a source is worth examining in more depth
• Quickly move on to more relevant sources
• Increase the quality of the information you consume

While this preliminary evaluation is an important step in the research process, you should engage with sources more deeply in order to adequately understand them.

In-depth evaluation

Begin your in-depth evaluation with any landmark studies in your field of research, or with sources that you’re sure are related to your research topic.

As you read, try to understand the connections between the sources. Look for:

• Key debates: What topics or questions are currently influencing research? How does the source respond to these key debates?
• Major publications or critics: Are there any specific texts or scholars that have greatly influenced the field? How does the source engage with them?
• Trends: Is the field currently dominated by particular theories or research methods ? How does the source respond to these?
• Gaps: Are there any oversights or weaknesses in the research?

Even sources whose conclusions you disagree with can be relevant, as they can strengthen your argument by offering alternative perspectives.

Every source should contribute to the debate about its topic by taking a clear position. This position and the conclusions the author comes to should be supported by evidence from direct observation or from other sources.

Most sources will use a mix of primary and secondary sources to form an argument . It is important to consider how the author uses these sources. A good argument should be based on analysis and critique, and there should be a logical relationship between evidence and conclusions.

To assess an argument’s strengths and weaknesses, ask:

• Does the evidence support the claim?
• How does the author use evidence? What theories, methods, or models do they use?
• Could the evidence be used to draw other conclusions? Can it be interpreted differently?
• How does the author situate their argument in the field? Do they agree or disagree with other scholars? Do they confirm or challenge established knowledge?

Situating a source in relation to other sources ( lateral reading ) can help you determine whether the author’s arguments and conclusions are reliable and how you will respond to them in your own writing.

If you want to know more about ChatGPT, AI tools , citation , and plagiarism , make sure to check out some of our other articles with explanations and examples.

• ChatGPT vs human editor
• ChatGPT citations
• Is ChatGPT trustworthy?
• Using ChatGPT for your studies
• What is ChatGPT?
• Chicago style
• Paraphrasing

 Plagiarism

• Types of plagiarism
• Self-plagiarism
• Avoiding plagiarism
• Academic integrity
• Consequences of plagiarism
• Common knowledge

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The AI-powered Citation Checker helps you avoid common mistakes such as:

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As you cannot possibly read every source related to your topic, it’s important to evaluate sources to assess their relevance. Use preliminary evaluation to determine whether a source is worth examining in more depth.

This involves:

• Reading abstracts , prefaces, introductions , and conclusions
• Looking at the table of contents to determine the scope of the work
• Consulting the index for key terms or the names of important scholars

Lateral reading is the act of evaluating the credibility of a source by comparing it with other sources. This allows you to:

A credible source should pass the CRAAP test  and follow these guidelines:

• The information should be up to date and current.
• The author and publication should be a trusted authority on the subject you are researching.
• The sources the author cited should be easy to find, clear, and unbiased.
• For a web source, the URL and layout should signify that it is trustworthy.

The CRAAP test is an acronym to help you evaluate the credibility of a source you are considering using. It is an important component of information literacy .

The CRAAP test has five main components:

• Currency: Is the source up to date?
• Relevance: Is the source relevant to your research?
• Authority: Where is the source published? Who is the author? Are they considered reputable and trustworthy in their field?
• Accuracy: Is the source supported by evidence? Are the claims cited correctly?
• Purpose: What was the motive behind publishing this source?

Scholarly sources are written by experts in their field and are typically subjected to peer review . They are intended for a scholarly audience, include a full bibliography, and use scholarly or technical language. For these reasons, they are typically considered credible sources .

Popular sources like magazines and news articles are typically written by journalists. These types of sources usually don’t include a bibliography and are written for a popular, rather than academic, audience. They are not always reliable and may be written from a biased or uninformed perspective, but they can still be cited in some contexts.

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The Literature Review

Primary and secondary sources, the literature review: primary and secondary sources.

• Searching the literature
• Grey literature
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On this page

• Primary vs secondary sources: The differences explained 

Can something be both a primary and secondary source?

Research for your literature review can be categorised as either primary or secondary in nature. The simplest definition of primary sources is either original information (such as survey data) or a first person account of an event (such as an interview transcript). Whereas secondary sources are any publshed or unpublished works that describe, summarise, analyse, evaluate, interpret or review primary source materials. Secondary sources can incorporate primary sources to support their arguments.

Ideally, good research should use a combination of both primary and secondary sources. For example, if a researcher were to investigate the introduction of a law and the impacts it had on a community, he/she might look at the transcripts of the parliamentary debates as well as the parliamentary commentary and news reporting surrounding the laws at the time. 

Examples of primary and secondary sources

Primary vs secondary sources: The differences explained

Finding primary sources

• VU Special Collections  - The Special Collections at Victoria University Library are a valuable research resource. The Collections have strong threads of radical literature, particularly Australian Communist literature, much of which is rare or unique. Women and urban planning also feature across the Collections. There are collections that give you a picture of the people who donated them like Ray Verrills, John McLaren, Sir Zelman Cowen, and Ruth & Maurie Crow. Other collections focus on Australia's neighbours – PNG and Timor-Leste.
• POLICY - Sharing the latest in policy knowledge and evidence, this database supports enhanced learning, collaboration and contribution.
• Indigenous Australia  -  The Indigenous Australia database represents the collections of the Aboriginal and Torres Strait Islander Commission Library.
• Australian Heritage Bibliography - Aboriginal and Torres Strait Islander Subset (AHB-ATSIS)  - AHB is a bibliographic database that indexes and abstracts articles from published and unpublished material on Australia's natural and cultural environment. The AHB-ATSIS subset contains records that specifically relate to the Aboriginal and Torres Strait Islander peoples.include journal articles, unpublished reports, books, videos and conference proceedings from many different sources around Australia. Emphasis is placed on reports written or commissioned by government and non-government heritage agencies throughout the country.
• ATSIhealth  - The Aboriginal and Torres Strait Islander Health Bibliography (ATSIhealth), compiled by Neil Thomson and Natalie Weissofner at the School of Indigenous Australian Studies, Kurongkurl Katitjin, Edith Cowan University, is a bibliographic database that indexes published and unpublished material on Australian Indigenous health. Source documents include theses, unpublished articles, government reports, conference papers, abstracts, book chapters, books, discussion and working papers, and statistical documents. 
• National Archive of Australia  - The National Archives of Australia holds the memory of our nation and keeps vital Australian Government records safe. 
• National Library of Australia: Manuscripts  - Manuscripts collection that is wide ranging and provides rich evidence of the lives and activities of Australians who have shaped our society.
• National Library of Australia: Printed ephemera  - The National Library has been selectively collecting Australian printed ephemera since the early 1960s as a record of Australian life and social customs, popular culture, national events, and issues of national concern.
• National Library of Australia: Oral history and folklore - The Library’s Oral History and Folklore Collection dates back to the 1950’s and includes a rich and diverse collection of interviews and recordings with Australians from all walks of life.
• Historic Hansard - Commonwealth of Australia parliamentary debates presented in an easy-to-read format for historians and other lovers of political speech.
• The Old Bailey Online - A fully searchable edition of the largest body of texts detailing the lives of non-elite people ever published, containing 197,745 criminal trials held at London's central criminal court.

Whether or not a source can be considered both primary and  secondary, depends on the context. In some instances, material may act as a secondary source for one research area, and as a primary source for another. For example, Niccolò Machiavelli’s The Prince , published in 1513, is an important secondary source for any study of the various Renaissance princes in the Medici family; but the same book is also a primary source for the political thought that was characteristic of the sixteenth century because it reflects the attitudes of a person living in the 1500s.

Source: Craver, 1999, as cited in University of South Australia Library. (2021, Oct 6).  Can something be a primary and secondary source?.  University of South Australia Library. https://guides.library.unisa.edu.au/historycultural/sourcetypes

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Lau F, Kuziemsky C, editors. Handbook of eHealth Evaluation: An Evidence-based Approach [Internet]. Victoria (BC): University of Victoria; 2017 Feb 27.

Handbook of eHealth Evaluation: An Evidence-based Approach [Internet].

Chapter 9 methods for literature reviews.

Guy Paré and Spyros Kitsiou .

9.1. Introduction

Literature reviews play a critical role in scholarship because science remains, first and foremost, a cumulative endeavour ( vom Brocke et al., 2009 ). As in any academic discipline, rigorous knowledge syntheses are becoming indispensable in keeping up with an exponentially growing eHealth literature, assisting practitioners, academics, and graduate students in finding, evaluating, and synthesizing the contents of many empirical and conceptual papers. Among other methods, literature reviews are essential for: (a) identifying what has been written on a subject or topic; (b) determining the extent to which a specific research area reveals any interpretable trends or patterns; (c) aggregating empirical findings related to a narrow research question to support evidence-based practice; (d) generating new frameworks and theories; and (e) identifying topics or questions requiring more investigation ( Paré, Trudel, Jaana, & Kitsiou, 2015 ).

Literature reviews can take two major forms. The most prevalent one is the “literature review” or “background” section within a journal paper or a chapter in a graduate thesis. This section synthesizes the extant literature and usually identifies the gaps in knowledge that the empirical study addresses ( Sylvester, Tate, & Johnstone, 2013 ). It may also provide a theoretical foundation for the proposed study, substantiate the presence of the research problem, justify the research as one that contributes something new to the cumulated knowledge, or validate the methods and approaches for the proposed study ( Hart, 1998 ; Levy & Ellis, 2006 ).

The second form of literature review, which is the focus of this chapter, constitutes an original and valuable work of research in and of itself ( Paré et al., 2015 ). Rather than providing a base for a researcher’s own work, it creates a solid starting point for all members of the community interested in a particular area or topic ( Mulrow, 1987 ). The so-called “review article” is a journal-length paper which has an overarching purpose to synthesize the literature in a field, without collecting or analyzing any primary data ( Green, Johnson, & Adams, 2006 ).

When appropriately conducted, review articles represent powerful information sources for practitioners looking for state-of-the art evidence to guide their decision-making and work practices ( Paré et al., 2015 ). Further, high-quality reviews become frequently cited pieces of work which researchers seek out as a first clear outline of the literature when undertaking empirical studies ( Cooper, 1988 ; Rowe, 2014 ). Scholars who track and gauge the impact of articles have found that review papers are cited and downloaded more often than any other type of published article ( Cronin, Ryan, & Coughlan, 2008 ; Montori, Wilczynski, Morgan, Haynes, & Hedges, 2003 ; Patsopoulos, Analatos, & Ioannidis, 2005 ). The reason for their popularity may be the fact that reading the review enables one to have an overview, if not a detailed knowledge of the area in question, as well as references to the most useful primary sources ( Cronin et al., 2008 ). Although they are not easy to conduct, the commitment to complete a review article provides a tremendous service to one’s academic community ( Paré et al., 2015 ; Petticrew & Roberts, 2006 ). Most, if not all, peer-reviewed journals in the fields of medical informatics publish review articles of some type.

The main objectives of this chapter are fourfold: (a) to provide an overview of the major steps and activities involved in conducting a stand-alone literature review; (b) to describe and contrast the different types of review articles that can contribute to the eHealth knowledge base; (c) to illustrate each review type with one or two examples from the eHealth literature; and (d) to provide a series of recommendations for prospective authors of review articles in this domain.

9.2. Overview of the Literature Review Process and Steps

As explained in Templier and Paré (2015) , there are six generic steps involved in conducting a review article:

• formulating the research question(s) and objective(s),
• searching the extant literature,
• screening for inclusion,
• assessing the quality of primary studies,
• extracting data, and
• analyzing data.

Although these steps are presented here in sequential order, one must keep in mind that the review process can be iterative and that many activities can be initiated during the planning stage and later refined during subsequent phases ( Finfgeld-Connett & Johnson, 2013 ; Kitchenham & Charters, 2007 ).

Formulating the research question(s) and objective(s): As a first step, members of the review team must appropriately justify the need for the review itself ( Petticrew & Roberts, 2006 ), identify the review’s main objective(s) ( Okoli & Schabram, 2010 ), and define the concepts or variables at the heart of their synthesis ( Cooper & Hedges, 2009 ; Webster & Watson, 2002 ). Importantly, they also need to articulate the research question(s) they propose to investigate ( Kitchenham & Charters, 2007 ). In this regard, we concur with Jesson, Matheson, and Lacey (2011) that clearly articulated research questions are key ingredients that guide the entire review methodology; they underscore the type of information that is needed, inform the search for and selection of relevant literature, and guide or orient the subsequent analysis. Searching the extant literature: The next step consists of searching the literature and making decisions about the suitability of material to be considered in the review ( Cooper, 1988 ). There exist three main coverage strategies. First, exhaustive coverage means an effort is made to be as comprehensive as possible in order to ensure that all relevant studies, published and unpublished, are included in the review and, thus, conclusions are based on this all-inclusive knowledge base. The second type of coverage consists of presenting materials that are representative of most other works in a given field or area. Often authors who adopt this strategy will search for relevant articles in a small number of top-tier journals in a field ( Paré et al., 2015 ). In the third strategy, the review team concentrates on prior works that have been central or pivotal to a particular topic. This may include empirical studies or conceptual papers that initiated a line of investigation, changed how problems or questions were framed, introduced new methods or concepts, or engendered important debate ( Cooper, 1988 ). Screening for inclusion: The following step consists of evaluating the applicability of the material identified in the preceding step ( Levy & Ellis, 2006 ; vom Brocke et al., 2009 ). Once a group of potential studies has been identified, members of the review team must screen them to determine their relevance ( Petticrew & Roberts, 2006 ). A set of predetermined rules provides a basis for including or excluding certain studies. This exercise requires a significant investment on the part of researchers, who must ensure enhanced objectivity and avoid biases or mistakes. As discussed later in this chapter, for certain types of reviews there must be at least two independent reviewers involved in the screening process and a procedure to resolve disagreements must also be in place ( Liberati et al., 2009 ; Shea et al., 2009 ). Assessing the quality of primary studies: In addition to screening material for inclusion, members of the review team may need to assess the scientific quality of the selected studies, that is, appraise the rigour of the research design and methods. Such formal assessment, which is usually conducted independently by at least two coders, helps members of the review team refine which studies to include in the final sample, determine whether or not the differences in quality may affect their conclusions, or guide how they analyze the data and interpret the findings ( Petticrew & Roberts, 2006 ). Ascribing quality scores to each primary study or considering through domain-based evaluations which study components have or have not been designed and executed appropriately makes it possible to reflect on the extent to which the selected study addresses possible biases and maximizes validity ( Shea et al., 2009 ). Extracting data: The following step involves gathering or extracting applicable information from each primary study included in the sample and deciding what is relevant to the problem of interest ( Cooper & Hedges, 2009 ). Indeed, the type of data that should be recorded mainly depends on the initial research questions ( Okoli & Schabram, 2010 ). However, important information may also be gathered about how, when, where and by whom the primary study was conducted, the research design and methods, or qualitative/quantitative results ( Cooper & Hedges, 2009 ). Analyzing and synthesizing data : As a final step, members of the review team must collate, summarize, aggregate, organize, and compare the evidence extracted from the included studies. The extracted data must be presented in a meaningful way that suggests a new contribution to the extant literature ( Jesson et al., 2011 ). Webster and Watson (2002) warn researchers that literature reviews should be much more than lists of papers and should provide a coherent lens to make sense of extant knowledge on a given topic. There exist several methods and techniques for synthesizing quantitative (e.g., frequency analysis, meta-analysis) and qualitative (e.g., grounded theory, narrative analysis, meta-ethnography) evidence ( Dixon-Woods, Agarwal, Jones, Young, & Sutton, 2005 ; Thomas & Harden, 2008 ).

9.3. Types of Review Articles and Brief Illustrations

EHealth researchers have at their disposal a number of approaches and methods for making sense out of existing literature, all with the purpose of casting current research findings into historical contexts or explaining contradictions that might exist among a set of primary research studies conducted on a particular topic. Our classification scheme is largely inspired from Paré and colleagues’ (2015) typology. Below we present and illustrate those review types that we feel are central to the growth and development of the eHealth domain.

9.3.1. Narrative Reviews

The narrative review is the “traditional” way of reviewing the extant literature and is skewed towards a qualitative interpretation of prior knowledge ( Sylvester et al., 2013 ). Put simply, a narrative review attempts to summarize or synthesize what has been written on a particular topic but does not seek generalization or cumulative knowledge from what is reviewed ( Davies, 2000 ; Green et al., 2006 ). Instead, the review team often undertakes the task of accumulating and synthesizing the literature to demonstrate the value of a particular point of view ( Baumeister & Leary, 1997 ). As such, reviewers may selectively ignore or limit the attention paid to certain studies in order to make a point. In this rather unsystematic approach, the selection of information from primary articles is subjective, lacks explicit criteria for inclusion and can lead to biased interpretations or inferences ( Green et al., 2006 ). There are several narrative reviews in the particular eHealth domain, as in all fields, which follow such an unstructured approach ( Silva et al., 2015 ; Paul et al., 2015 ).

Despite these criticisms, this type of review can be very useful in gathering together a volume of literature in a specific subject area and synthesizing it. As mentioned above, its primary purpose is to provide the reader with a comprehensive background for understanding current knowledge and highlighting the significance of new research ( Cronin et al., 2008 ). Faculty like to use narrative reviews in the classroom because they are often more up to date than textbooks, provide a single source for students to reference, and expose students to peer-reviewed literature ( Green et al., 2006 ). For researchers, narrative reviews can inspire research ideas by identifying gaps or inconsistencies in a body of knowledge, thus helping researchers to determine research questions or formulate hypotheses. Importantly, narrative reviews can also be used as educational articles to bring practitioners up to date with certain topics of issues ( Green et al., 2006 ).

Recently, there have been several efforts to introduce more rigour in narrative reviews that will elucidate common pitfalls and bring changes into their publication standards. Information systems researchers, among others, have contributed to advancing knowledge on how to structure a “traditional” review. For instance, Levy and Ellis (2006) proposed a generic framework for conducting such reviews. Their model follows the systematic data processing approach comprised of three steps, namely: (a) literature search and screening; (b) data extraction and analysis; and (c) writing the literature review. They provide detailed and very helpful instructions on how to conduct each step of the review process. As another methodological contribution, vom Brocke et al. (2009) offered a series of guidelines for conducting literature reviews, with a particular focus on how to search and extract the relevant body of knowledge. Last, Bandara, Miskon, and Fielt (2011) proposed a structured, predefined and tool-supported method to identify primary studies within a feasible scope, extract relevant content from identified articles, synthesize and analyze the findings, and effectively write and present the results of the literature review. We highly recommend that prospective authors of narrative reviews consult these useful sources before embarking on their work.

Darlow and Wen (2015) provide a good example of a highly structured narrative review in the eHealth field. These authors synthesized published articles that describe the development process of mobile health ( m-health ) interventions for patients’ cancer care self-management. As in most narrative reviews, the scope of the research questions being investigated is broad: (a) how development of these systems are carried out; (b) which methods are used to investigate these systems; and (c) what conclusions can be drawn as a result of the development of these systems. To provide clear answers to these questions, a literature search was conducted on six electronic databases and Google Scholar . The search was performed using several terms and free text words, combining them in an appropriate manner. Four inclusion and three exclusion criteria were utilized during the screening process. Both authors independently reviewed each of the identified articles to determine eligibility and extract study information. A flow diagram shows the number of studies identified, screened, and included or excluded at each stage of study selection. In terms of contributions, this review provides a series of practical recommendations for m-health intervention development.

9.3.2. Descriptive or Mapping Reviews

The primary goal of a descriptive review is to determine the extent to which a body of knowledge in a particular research topic reveals any interpretable pattern or trend with respect to pre-existing propositions, theories, methodologies or findings ( King & He, 2005 ; Paré et al., 2015 ). In contrast with narrative reviews, descriptive reviews follow a systematic and transparent procedure, including searching, screening and classifying studies ( Petersen, Vakkalanka, & Kuzniarz, 2015 ). Indeed, structured search methods are used to form a representative sample of a larger group of published works ( Paré et al., 2015 ). Further, authors of descriptive reviews extract from each study certain characteristics of interest, such as publication year, research methods, data collection techniques, and direction or strength of research outcomes (e.g., positive, negative, or non-significant) in the form of frequency analysis to produce quantitative results ( Sylvester et al., 2013 ). In essence, each study included in a descriptive review is treated as the unit of analysis and the published literature as a whole provides a database from which the authors attempt to identify any interpretable trends or draw overall conclusions about the merits of existing conceptualizations, propositions, methods or findings ( Paré et al., 2015 ). In doing so, a descriptive review may claim that its findings represent the state of the art in a particular domain ( King & He, 2005 ).

In the fields of health sciences and medical informatics, reviews that focus on examining the range, nature and evolution of a topic area are described by Anderson, Allen, Peckham, and Goodwin (2008) as mapping reviews . Like descriptive reviews, the research questions are generic and usually relate to publication patterns and trends. There is no preconceived plan to systematically review all of the literature although this can be done. Instead, researchers often present studies that are representative of most works published in a particular area and they consider a specific time frame to be mapped.

An example of this approach in the eHealth domain is offered by DeShazo, Lavallie, and Wolf (2009). The purpose of this descriptive or mapping review was to characterize publication trends in the medical informatics literature over a 20-year period (1987 to 2006). To achieve this ambitious objective, the authors performed a bibliometric analysis of medical informatics citations indexed in medline using publication trends, journal frequencies, impact factors, Medical Subject Headings (MeSH) term frequencies, and characteristics of citations. Findings revealed that there were over 77,000 medical informatics articles published during the covered period in numerous journals and that the average annual growth rate was 12%. The MeSH term analysis also suggested a strong interdisciplinary trend. Finally, average impact scores increased over time with two notable growth periods. Overall, patterns in research outputs that seem to characterize the historic trends and current components of the field of medical informatics suggest it may be a maturing discipline (DeShazo et al., 2009).

9.3.3. Scoping Reviews

Scoping reviews attempt to provide an initial indication of the potential size and nature of the extant literature on an emergent topic (Arksey & O’Malley, 2005; Daudt, van Mossel, & Scott, 2013 ; Levac, Colquhoun, & O’Brien, 2010). A scoping review may be conducted to examine the extent, range and nature of research activities in a particular area, determine the value of undertaking a full systematic review (discussed next), or identify research gaps in the extant literature ( Paré et al., 2015 ). In line with their main objective, scoping reviews usually conclude with the presentation of a detailed research agenda for future works along with potential implications for both practice and research.

Unlike narrative and descriptive reviews, the whole point of scoping the field is to be as comprehensive as possible, including grey literature (Arksey & O’Malley, 2005). Inclusion and exclusion criteria must be established to help researchers eliminate studies that are not aligned with the research questions. It is also recommended that at least two independent coders review abstracts yielded from the search strategy and then the full articles for study selection ( Daudt et al., 2013 ). The synthesized evidence from content or thematic analysis is relatively easy to present in tabular form (Arksey & O’Malley, 2005; Thomas & Harden, 2008 ).

One of the most highly cited scoping reviews in the eHealth domain was published by Archer, Fevrier-Thomas, Lokker, McKibbon, and Straus (2011) . These authors reviewed the existing literature on personal health record ( phr ) systems including design, functionality, implementation, applications, outcomes, and benefits. Seven databases were searched from 1985 to March 2010. Several search terms relating to phr s were used during this process. Two authors independently screened titles and abstracts to determine inclusion status. A second screen of full-text articles, again by two independent members of the research team, ensured that the studies described phr s. All in all, 130 articles met the criteria and their data were extracted manually into a database. The authors concluded that although there is a large amount of survey, observational, cohort/panel, and anecdotal evidence of phr benefits and satisfaction for patients, more research is needed to evaluate the results of phr implementations. Their in-depth analysis of the literature signalled that there is little solid evidence from randomized controlled trials or other studies through the use of phr s. Hence, they suggested that more research is needed that addresses the current lack of understanding of optimal functionality and usability of these systems, and how they can play a beneficial role in supporting patient self-management ( Archer et al., 2011 ).

9.3.4. Forms of Aggregative Reviews

Healthcare providers, practitioners, and policy-makers are nowadays overwhelmed with large volumes of information, including research-based evidence from numerous clinical trials and evaluation studies, assessing the effectiveness of health information technologies and interventions ( Ammenwerth & de Keizer, 2004 ; Deshazo et al., 2009 ). It is unrealistic to expect that all these disparate actors will have the time, skills, and necessary resources to identify the available evidence in the area of their expertise and consider it when making decisions. Systematic reviews that involve the rigorous application of scientific strategies aimed at limiting subjectivity and bias (i.e., systematic and random errors) can respond to this challenge.

Systematic reviews attempt to aggregate, appraise, and synthesize in a single source all empirical evidence that meet a set of previously specified eligibility criteria in order to answer a clearly formulated and often narrow research question on a particular topic of interest to support evidence-based practice ( Liberati et al., 2009 ). They adhere closely to explicit scientific principles ( Liberati et al., 2009 ) and rigorous methodological guidelines (Higgins & Green, 2008) aimed at reducing random and systematic errors that can lead to deviations from the truth in results or inferences. The use of explicit methods allows systematic reviews to aggregate a large body of research evidence, assess whether effects or relationships are in the same direction and of the same general magnitude, explain possible inconsistencies between study results, and determine the strength of the overall evidence for every outcome of interest based on the quality of included studies and the general consistency among them ( Cook, Mulrow, & Haynes, 1997 ). The main procedures of a systematic review involve:

• Formulating a review question and developing a search strategy based on explicit inclusion criteria for the identification of eligible studies (usually described in the context of a detailed review protocol).
• Searching for eligible studies using multiple databases and information sources, including grey literature sources, without any language restrictions.
• Selecting studies, extracting data, and assessing risk of bias in a duplicate manner using two independent reviewers to avoid random or systematic errors in the process.
• Analyzing data using quantitative or qualitative methods.
• Presenting results in summary of findings tables.
• Interpreting results and drawing conclusions.

Many systematic reviews, but not all, use statistical methods to combine the results of independent studies into a single quantitative estimate or summary effect size. Known as meta-analyses , these reviews use specific data extraction and statistical techniques (e.g., network, frequentist, or Bayesian meta-analyses) to calculate from each study by outcome of interest an effect size along with a confidence interval that reflects the degree of uncertainty behind the point estimate of effect ( Borenstein, Hedges, Higgins, & Rothstein, 2009 ; Deeks, Higgins, & Altman, 2008 ). Subsequently, they use fixed or random-effects analysis models to combine the results of the included studies, assess statistical heterogeneity, and calculate a weighted average of the effect estimates from the different studies, taking into account their sample sizes. The summary effect size is a value that reflects the average magnitude of the intervention effect for a particular outcome of interest or, more generally, the strength of a relationship between two variables across all studies included in the systematic review. By statistically combining data from multiple studies, meta-analyses can create more precise and reliable estimates of intervention effects than those derived from individual studies alone, when these are examined independently as discrete sources of information.

The review by Gurol-Urganci, de Jongh, Vodopivec-Jamsek, Atun, and Car (2013) on the effects of mobile phone messaging reminders for attendance at healthcare appointments is an illustrative example of a high-quality systematic review with meta-analysis. Missed appointments are a major cause of inefficiency in healthcare delivery with substantial monetary costs to health systems. These authors sought to assess whether mobile phone-based appointment reminders delivered through Short Message Service ( sms ) or Multimedia Messaging Service ( mms ) are effective in improving rates of patient attendance and reducing overall costs. To this end, they conducted a comprehensive search on multiple databases using highly sensitive search strategies without language or publication-type restrictions to identify all rct s that are eligible for inclusion. In order to minimize the risk of omitting eligible studies not captured by the original search, they supplemented all electronic searches with manual screening of trial registers and references contained in the included studies. Study selection, data extraction, and risk of bias assessments were performed inde­­pen­dently by two coders using standardized methods to ensure consistency and to eliminate potential errors. Findings from eight rct s involving 6,615 participants were pooled into meta-analyses to calculate the magnitude of effects that mobile text message reminders have on the rate of attendance at healthcare appointments compared to no reminders and phone call reminders.

Meta-analyses are regarded as powerful tools for deriving meaningful conclusions. However, there are situations in which it is neither reasonable nor appropriate to pool studies together using meta-analytic methods simply because there is extensive clinical heterogeneity between the included studies or variation in measurement tools, comparisons, or outcomes of interest. In these cases, systematic reviews can use qualitative synthesis methods such as vote counting, content analysis, classification schemes and tabulations, as an alternative approach to narratively synthesize the results of the independent studies included in the review. This form of review is known as qualitative systematic review.

A rigorous example of one such review in the eHealth domain is presented by Mickan, Atherton, Roberts, Heneghan, and Tilson (2014) on the use of handheld computers by healthcare professionals and their impact on access to information and clinical decision-making. In line with the methodological guide­lines for systematic reviews, these authors: (a) developed and registered with prospero ( www.crd.york.ac.uk/ prospero / ) an a priori review protocol; (b) conducted comprehensive searches for eligible studies using multiple databases and other supplementary strategies (e.g., forward searches); and (c) subsequently carried out study selection, data extraction, and risk of bias assessments in a duplicate manner to eliminate potential errors in the review process. Heterogeneity between the included studies in terms of reported outcomes and measures precluded the use of meta-analytic methods. To this end, the authors resorted to using narrative analysis and synthesis to describe the effectiveness of handheld computers on accessing information for clinical knowledge, adherence to safety and clinical quality guidelines, and diagnostic decision-making.

In recent years, the number of systematic reviews in the field of health informatics has increased considerably. Systematic reviews with discordant findings can cause great confusion and make it difficult for decision-makers to interpret the review-level evidence ( Moher, 2013 ). Therefore, there is a growing need for appraisal and synthesis of prior systematic reviews to ensure that decision-making is constantly informed by the best available accumulated evidence. Umbrella reviews , also known as overviews of systematic reviews, are tertiary types of evidence synthesis that aim to accomplish this; that is, they aim to compare and contrast findings from multiple systematic reviews and meta-analyses ( Becker & Oxman, 2008 ). Umbrella reviews generally adhere to the same principles and rigorous methodological guidelines used in systematic reviews. However, the unit of analysis in umbrella reviews is the systematic review rather than the primary study ( Becker & Oxman, 2008 ). Unlike systematic reviews that have a narrow focus of inquiry, umbrella reviews focus on broader research topics for which there are several potential interventions ( Smith, Devane, Begley, & Clarke, 2011 ). A recent umbrella review on the effects of home telemonitoring interventions for patients with heart failure critically appraised, compared, and synthesized evidence from 15 systematic reviews to investigate which types of home telemonitoring technologies and forms of interventions are more effective in reducing mortality and hospital admissions ( Kitsiou, Paré, & Jaana, 2015 ).

9.3.5. Realist Reviews

Realist reviews are theory-driven interpretative reviews developed to inform, enhance, or supplement conventional systematic reviews by making sense of heterogeneous evidence about complex interventions applied in diverse contexts in a way that informs policy decision-making ( Greenhalgh, Wong, Westhorp, & Pawson, 2011 ). They originated from criticisms of positivist systematic reviews which centre on their “simplistic” underlying assumptions ( Oates, 2011 ). As explained above, systematic reviews seek to identify causation. Such logic is appropriate for fields like medicine and education where findings of randomized controlled trials can be aggregated to see whether a new treatment or intervention does improve outcomes. However, many argue that it is not possible to establish such direct causal links between interventions and outcomes in fields such as social policy, management, and information systems where for any intervention there is unlikely to be a regular or consistent outcome ( Oates, 2011 ; Pawson, 2006 ; Rousseau, Manning, & Denyer, 2008 ).

To circumvent these limitations, Pawson, Greenhalgh, Harvey, and Walshe (2005) have proposed a new approach for synthesizing knowledge that seeks to unpack the mechanism of how “complex interventions” work in particular contexts. The basic research question — what works? — which is usually associated with systematic reviews changes to: what is it about this intervention that works, for whom, in what circumstances, in what respects and why? Realist reviews have no particular preference for either quantitative or qualitative evidence. As a theory-building approach, a realist review usually starts by articulating likely underlying mechanisms and then scrutinizes available evidence to find out whether and where these mechanisms are applicable ( Shepperd et al., 2009 ). Primary studies found in the extant literature are viewed as case studies which can test and modify the initial theories ( Rousseau et al., 2008 ).

The main objective pursued in the realist review conducted by Otte-Trojel, de Bont, Rundall, and van de Klundert (2014) was to examine how patient portals contribute to health service delivery and patient outcomes. The specific goals were to investigate how outcomes are produced and, most importantly, how variations in outcomes can be explained. The research team started with an exploratory review of background documents and research studies to identify ways in which patient portals may contribute to health service delivery and patient outcomes. The authors identified six main ways which represent “educated guesses” to be tested against the data in the evaluation studies. These studies were identified through a formal and systematic search in four databases between 2003 and 2013. Two members of the research team selected the articles using a pre-established list of inclusion and exclusion criteria and following a two-step procedure. The authors then extracted data from the selected articles and created several tables, one for each outcome category. They organized information to bring forward those mechanisms where patient portals contribute to outcomes and the variation in outcomes across different contexts.

9.3.6. Critical Reviews

Lastly, critical reviews aim to provide a critical evaluation and interpretive analysis of existing literature on a particular topic of interest to reveal strengths, weaknesses, contradictions, controversies, inconsistencies, and/or other important issues with respect to theories, hypotheses, research methods or results ( Baumeister & Leary, 1997 ; Kirkevold, 1997 ). Unlike other review types, critical reviews attempt to take a reflective account of the research that has been done in a particular area of interest, and assess its credibility by using appraisal instruments or critical interpretive methods. In this way, critical reviews attempt to constructively inform other scholars about the weaknesses of prior research and strengthen knowledge development by giving focus and direction to studies for further improvement ( Kirkevold, 1997 ).

Kitsiou, Paré, and Jaana (2013) provide an example of a critical review that assessed the methodological quality of prior systematic reviews of home telemonitoring studies for chronic patients. The authors conducted a comprehensive search on multiple databases to identify eligible reviews and subsequently used a validated instrument to conduct an in-depth quality appraisal. Results indicate that the majority of systematic reviews in this particular area suffer from important methodological flaws and biases that impair their internal validity and limit their usefulness for clinical and decision-making purposes. To this end, they provide a number of recommendations to strengthen knowledge development towards improving the design and execution of future reviews on home telemonitoring.

9.4. Summary

Table 9.1 outlines the main types of literature reviews that were described in the previous sub-sections and summarizes the main characteristics that distinguish one review type from another. It also includes key references to methodological guidelines and useful sources that can be used by eHealth scholars and researchers for planning and developing reviews.

Typology of Literature Reviews (adapted from Paré et al., 2015).

As shown in Table 9.1 , each review type addresses different kinds of research questions or objectives, which subsequently define and dictate the methods and approaches that need to be used to achieve the overarching goal(s) of the review. For example, in the case of narrative reviews, there is greater flexibility in searching and synthesizing articles ( Green et al., 2006 ). Researchers are often relatively free to use a diversity of approaches to search, identify, and select relevant scientific articles, describe their operational characteristics, present how the individual studies fit together, and formulate conclusions. On the other hand, systematic reviews are characterized by their high level of systematicity, rigour, and use of explicit methods, based on an “a priori” review plan that aims to minimize bias in the analysis and synthesis process (Higgins & Green, 2008). Some reviews are exploratory in nature (e.g., scoping/mapping reviews), whereas others may be conducted to discover patterns (e.g., descriptive reviews) or involve a synthesis approach that may include the critical analysis of prior research ( Paré et al., 2015 ). Hence, in order to select the most appropriate type of review, it is critical to know before embarking on a review project, why the research synthesis is conducted and what type of methods are best aligned with the pursued goals.

9.5. Concluding Remarks

In light of the increased use of evidence-based practice and research generating stronger evidence ( Grady et al., 2011 ; Lyden et al., 2013 ), review articles have become essential tools for summarizing, synthesizing, integrating or critically appraising prior knowledge in the eHealth field. As mentioned earlier, when rigorously conducted review articles represent powerful information sources for eHealth scholars and practitioners looking for state-of-the-art evidence. The typology of literature reviews we used herein will allow eHealth researchers, graduate students and practitioners to gain a better understanding of the similarities and differences between review types.

We must stress that this classification scheme does not privilege any specific type of review as being of higher quality than another ( Paré et al., 2015 ). As explained above, each type of review has its own strengths and limitations. Having said that, we realize that the methodological rigour of any review — be it qualitative, quantitative or mixed — is a critical aspect that should be considered seriously by prospective authors. In the present context, the notion of rigour refers to the reliability and validity of the review process described in section 9.2. For one thing, reliability is related to the reproducibility of the review process and steps, which is facilitated by a comprehensive documentation of the literature search process, extraction, coding and analysis performed in the review. Whether the search is comprehensive or not, whether it involves a methodical approach for data extraction and synthesis or not, it is important that the review documents in an explicit and transparent manner the steps and approach that were used in the process of its development. Next, validity characterizes the degree to which the review process was conducted appropriately. It goes beyond documentation and reflects decisions related to the selection of the sources, the search terms used, the period of time covered, the articles selected in the search, and the application of backward and forward searches ( vom Brocke et al., 2009 ). In short, the rigour of any review article is reflected by the explicitness of its methods (i.e., transparency) and the soundness of the approach used. We refer those interested in the concepts of rigour and quality to the work of Templier and Paré (2015) which offers a detailed set of methodological guidelines for conducting and evaluating various types of review articles.

To conclude, our main objective in this chapter was to demystify the various types of literature reviews that are central to the continuous development of the eHealth field. It is our hope that our descriptive account will serve as a valuable source for those conducting, evaluating or using reviews in this important and growing domain.

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• Cite this Page Paré G, Kitsiou S. Chapter 9 Methods for Literature Reviews. In: Lau F, Kuziemsky C, editors. Handbook of eHealth Evaluation: An Evidence-based Approach [Internet]. Victoria (BC): University of Victoria; 2017 Feb 27.
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• Introduction
• Overview of the Literature Review Process and Steps
• Types of Review Articles and Brief Illustrations
• Concluding Remarks

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Literature Review: The What, Why and How-to Guide: Evaluating Sources & Literature Reviews

• Literature Reviews?
• Strategies to Finding Sources
• Keeping up with Research!
• Evaluating Sources & Literature Reviews
• Organizing for Writing
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Evaluating Literature Reviews and Sources

• Tips for Evaluating Sources (Print vs. Internet Sources) Excellent page that will guide you on what to ask to determine if your source is a reliable one. Check the other topics in the guide: Evaluating Bibliographic Citations and Evaluation During Reading on the left side menu.

Criteria to evaluate sources:

• Authority : Who is the author? What are the author's credentials and areas of expertise? Is he or she affiliated with a university?
• Usefulness : How this source related to your topic? How current or relevant it is to your topic?
• Reliability : Does the information comes from a reliable, trusted source such as an academic journal?
• Critically Analyzing Information Sources: Critical Appraisal and Analysis (Cornell University Library) Ten things to look for when you evaluate an information source.

Reading Critically

Reading critically (summary from how to read academic texts critically).

• Who is the author? What is his/her standing in the field?
• What is the author’s purpose? To offer advice, make practical suggestions, solve a specific problem, critique or clarify?
• Note the experts in the field: are there specific names/labs that are frequently cited?
• Pay attention to methodology: is it sound? what testing procedures, subjects, materials were used?
• Note conflicting theories, methodologies, and results. Are there any assumptions being made by most/some researchers?
• Theories: have they evolved over time?
• Evaluate and synthesize the findings and conclusions. How does this study contribute to your project?
• How to Read Academic Texts Critically Excellent document about how best to read critically academic articles and other texts.
• How to Read an Academic Article This is an excellent paper that teach you how to read an academic paper, how to determine if it is something to set aside, or something to read deeply. Good advice to organize your literature for the Literature Review or just reading for classes.
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Literature Review

Where to search when doing a literature review.

• Find examples of literature reviews
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• Grey literature

Aim to be as comprehensive as possible when conducting a literature review. Knowing exactly where to search for information is important.

Work through the steps to find out the best databases to search for information on your research topic.

1. Start with research databases

Scopus and Web of Science are good databases to start with for any research topic and literature review.

• Scopus Scopus is a large multidisciplinary database covering published material in the humanities and sciences. It also provides citation analysis of authors and subject areas. Searching Scopus tutorial - Includes access to Scival via expanded top menu (Elsevier personal registration required).
• Web of Science - Core Collection The leading citation index' of scholarly literature, chemical reactions and author information. Includes citation databases: Sciences Expanded (1965+), Social Sciences (1965+), Arts & Humanities (1975+). Conference Proceedings (1990+), Emerging Sources Citation (2005+) , Current Chemical Reactions (1985+) and Index Chemicus (1993+) Access InCites benchmarking & analytics tools via the menu bar at the top of the screen.

2. Focus your search with specific databases

Select two or three discipline/specialist databases to conduct your search for comprehensive results.

Our subject guides will help you find databases relevant to major subject areas in each discipline and specific materials relevant to your research.

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3. Find books, theses and more

If you're looking for a specific medium (book, thesis, journal, etc.) for your research, try the following:

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Chapter 5: Evaluating Sources

Learning objectives.

At the conclusion of this chapter, you will be able to:

• Critically evaluate the sources of the information you have found.
• Evaluate the content of selected material for your purposes.

5.1 Overview of evaluation of sources

Searching for information is often nonlinear and iterative, requiring the evaluation of a range of information sources and the mental flexibility to pursue alternate avenues as new understanding develops. ( Association of College & Research Libraries, 2016 ).

You developed a viable research question, compiled a list of subject headings and keywords and spent a great deal of time searching the literature of your discipline or topic for sources. It’s now time to evaluate all of the information you found. Not only do you want to be sure of the source and the quality of the information, but you also want to determine whether each item is appropriate fit for your own review. This is also the point at which you make sure that you have searched out publications for all areas of your research question and go back into the literature for another search, if necessary.

In general, when we discuss evaluation of sources we are talking about looking at quality, accuracy, relevance, bias, reputation, currency, and credibility factors in a specific work, whether it’s a book, ebook, article, website, or blog posting. Before you include a source in your literature review, you should clearly understand what it is and why you are including it. According to Bennard et al., ( 2014 ), “Using inaccurate, irrelevant, or poorly researched sources can affect the quality of your own work.” (para. 4).

When evaluating a work for inclusion in, or exclusion from, your literature review, ask yourself a series of questions about each source.

5.1.1 Evaluating books

For primary and secondary sources you located in your search, use the ASAP mnemonic to evaluate inclusion in your literature review:

5.1.1.1 Age

Is it outdated? The answer to this question depends on your topic. If you are comparing historical classroom management techniques, something from 1965 might be appropriate. In Nursing, unless you are doing a historical comparison, a textbook from 5 years ago might be too dated for your needs.

A General Rule of Thumb:

5 years, maximum: medicine, health, education, technology, science 10-20 years: history, literature, art

5.1.1.2 Sources

Check reference or bibliography sources as well as those listed in footnotes or endnotes. Skim the list to see what kinds of sources the author used. When were the sources published? If the author is primarily citing works from 10 or 15 years ago, the book may not be what you need.

5.1.1.3 Author

Does the author have the credentials to write on the topic? Does the author have an academic degree or research grant funding? What else has the author published on the topic?

5.1.1.4 Publisher

Look for academic presses, including university presses. Books published under popular press imprints (such as Random House or Macmillan, in the U.S.) will not present scholarly research in the same way as Sage, Oxford, Harvard, or the University of Washington Press.

Other questions to ask about the book you may want to include in your literature review:

• What is the book’s purpose? Why was it written? Who is the intended audience?
• What is the conclusion or argument? How well is the main argument or conclusion supported?
• Is it relevant to your research? How is it related to your research question?
• Do you see any evidence of bias or unsubstantiated data?

5.1.2 Evaluating websites

In your research, it is likely you will discover information on the web that you will want to include in your literature review. For example, if your review is related to the current policy issues in public education in the United States, a potentially relevant information source may be a document located on the National Center for Education Statistics (NCES) website titled The Condition of Education 2017 . Likewise, for nursing, an article titled Discussing Vaccination with Concerned Patients: An Evidence-Based Resource for Healthcare Providers is available through the nursingcenter.com website. How do you evaluate these resources, and others like them?

Use the RADAR mnemonic ( Mandalios, 2013 ) to evaluate internet sources:

5.1.2.1 Relevance

How did you find the website and how is it relevant to your topic?

• Was it recommended by a reliable source?
• Was it cited in a scholarly source, such as a peer-reviewed journal?
• Was it linked from a reputable site?

5.1.2.2 Authority

Look for the About page to find information about the purpose of the website . You may make a determination of its credibility based on what you find there. Does the page exhibit a particular point of view or bias? For example, a heart association or charter school may be promoting a particular perspective – how might that impact the objectivity of the information located on their site? Is there advertising or is there a product information attached to the content?

5.1.2.3 Date

• When was the page created?
• Is it kept up to date?
• Are the links current and functional?

5.1.2.4 Appearance

• Does the information presented appear to be factual?
• Is the language formal or academic?
• How does it compare to other information you have read on the topic?
• Are references or links to cited material included?

5.1.2.5 Reason

What is the web address or URL? This can give you a clue about the purpose of the website, which may be to debate, advocate, advertise or sell, campaign, or present information. Here are some common domains and their origins:

• .org – An advocacy website for an organization
• .com – A private or commercial site
• .net – A network organization or Internet provider/no longer frequently used
• .edu – The site of a higher educational institution
• .gov – A federal government site
• .wa.us – A state government site which may include public schools and community colleges
• .uk, .ca, .jm – A country site

Mike Caulfield ( 2017 ), the author of Web Literacy for Student Fact-Checkers , recommends a few simple strategies to evaluate a website (as well as social media):

• Check for previous work: Look around to see if someone else has already provided a synthesis of the research described.
• Go upstream to the source: Go “upstream” to the source of the claim. Most web content is not original. Get to the original source to understand the credibility and reliability of the information.
• Read laterally: Read laterally. Once you get to the source of a claim, read what other people say about the source (publication, author, etc.). The truth is in the network.

5.1.3 Evaluating journal articles

It is likely that most of the resources you locate for your review will be from the scholarly literature of your discipline or in your topic area. As we have already seen, peer-reviewed articles are written by and for experts in a field. They generally describe formal research studies or experiments with the purpose of providing insight on a topic. You may have located these articles through Google, Google Scholar, a subscription or open access database, or citation searching. You now may want to know how to evaluate the usefulness for your research. As with the other resources, you are again looking for authority, accuracy, reliability, relevance, currency, and scope. Looking at each article as a separate and unique artifact, consider these elements in your evaluation:

5.1.3.1 Credibility/Authority

ASK: Who is the author? Is this person considered an expert in their field?

• Search the author’s name in a general web search engine like Google.
• What are the researcher’s academic credentials?
• What else has this author written? Search by author in the databases and see how much they have published on any given subject.
• How often or frequently has this article been cited by other scholars?

Citation analysis is the study of the impact and assumed quality of an article, an author, or an institution, based on the number of times works and/or authors have been cited by others. Google Scholar is a good way to get at this information.

5.1.3.2 Accuracy

Check the facts. ASK:

• Can statistics be verified through other sources?
• Does this information seem to fit with what you have read in other sources?

5.1.3.3 Reliability/Objectivity

ASK: Is there an obvious bias? That doesn’t mean that you can’t use the information, it just means you need to take the bias into account.

• Is a particular point of view or bias immediately obvious, or does it seem objective at first glance?
• What point of view does the author represent? Are they clear about their point of view?
• Is the article an editorial that is trying to argue a position?
• Is the article in a publication with a particular editorial position?

5.1.3.4 Relevance

ASK: The hard questions:

• Is the information relevant to your topic/thesis?
• How does the article fit into the scope of the literature on this topic?
• Is the material too technical or too clinical?
• Is it too elementary or basic?
• Does the information support your thesis or help you answer your question, or is it a challenge to make some kind of connection?
• Does the information present an opposite point of view so you can show that you have addressed all sides of the argument in your paper?

5.1.3.5 Currency

• When was the source published?
• How important is current information to your topic, discipline, or paper type?
• Does older material add to the history of the research? Or do you need something more current to support your thesis?

5.1.3.6 Scope and Purpose

To determine and evaluate in this category, ASK:

• Is it a general work that provides an overview of the topic or is it specifically focused on only one aspect of your topic?
• Does the breadth of the work match your expectations?
• Is the article meant to inform, explain, persuade or sell something. Be aware of the purpose as you read the content and take that into consideration when deciding whether to use it or not.

For Nursing and other medical articles ASK:

• What are the research methods used in the article?
• Where does the method fall in the evidence pyramid? Systematic reviews and meta-analyses are the most credible, with articles that are opinions the least credible.

• Meta Analysis: A systematic review that uses quantitative methods to summarize the results.
• Systematic Review: An article in which the authors have systematically searched for, appraised, and summarized all of the medical literature on a specific topic.
• Randomized Controlled Trials (RCTs): RCTs include a randomized group of patients in an experimental group, as well as a control group. These groups are monitored for the variables/outcomes of interest.
• Cohort Study: Research identifies two groups (cohorts) of patients, one which did receive the exposure of interest, and one which did not, and follows these cohorts for a specified duration of time, in order to measure the outcome of interest.
• Case Study: Involves identifying patients who have the outcome of interest (cases) and control patients without the same outcome, and looks to see if they had the exposure of interest.
• Animal Research / Lab Studies: Information creation begins at the bottom of the pyramid: This is where ideas and laboratory research take place. Ideas turn into therapies and diagnostic tools, which are then tested with lab models and animals.
• Background Information / Expert Opinion: Handbooks, encyclopedias, and textbooks often provide a good foundation or introduction and often include generalized information about a condition. While background information presents a convenient summary, it typically takes about three years for this type of literature to be published.

5.1.4 Evaluating Social Media

Although social media (for example, Twitter or Facebook) is generally treated as an object under study rather than a source of information on a topic, the prevalence of social media as communication and sharing platforms must be acknowledged. It’s important to be skeptical of these sources, especially for inclusion in a literature review. However, as with any other web resource,you can evaluate a social media posting for authenticity by asking the following questions:

• Location of the source – Is the author in the place they are tweeting or posting about?
• Network – Who is in the author’s network and who follows the account?
• Content – Can the information be corroborated from other sources?
• Contextual updates – Does the author usually post or tweet on this topic? If so, what did past or updated posts say? Do they fill in more details?
• Reliability – does the author cite sources and are those sources reliable? ( Sheridan Libraries, 2017 )

5.2 In Summary

Another way to think about evaluation of sources is to ask the 5W questions:

• What type of document is it?
• Who created it?
• Why was the material published?
• When was it published?
• Where was the resource published?
• How was the information gathered and presented? ( Radom, 2017 )

Locating sources for your literature review by using discovery layers, library catalogs, databases, search engines, and other search platforms may take a great deal of time and effort. Does everything you found and retrieved have value or worth to you as you write your own literature review? If the resource has not met the criteria above and you can’t justify its place in your literature review, it doesn’t deserve to be mentioned in your work. Include high-quality materials that are current, accurate, credible, and most importantly relevant to your research question, hypothesis, or topic.

Evaluate a Website

Watch this short video :

Using a search engine like Google, do a quick search for a topic that interests you. Select a website from your list of results and evaluate it using the elements of website evaluation listed earlier in this chapter.

• How did you find the website?
• What is the domain name (the URL) of the site?
• What can you learn about the author/s of the site?
• When was the site last updated?
• Is it accurate based on what you know about the topic?
• Are there references?
• Do you notice any bias?
• Is the site functional? (re links working? Or do they lead to non-functional pages?)

Evaluate a Book

Select a subject specific book or ebook that you can access quickly and evaluate it based on the ASAP criteria.

Evaluate an Article

You can practice evaluation using the attached articles. You don’t need to spend a lot of time with the article, but see if you can identify each of the elements of evaluation. Remember the elements of evaluation for articles are:

• Authority/Credibility or Study Design for Nursing
• Reliability/Objectivity
• Scope and Purpose

For Education: Quality standards in e-learning: A matrix of analysis ( Frydenberg, 2002 ).

For Nursing: Beliefs and attitudes towards participating in genetic research ( Kerath et al, 2013 ).

Test Yourself

Check the Answer Key

For Nursing students: Your topic is the relationship between autism and vaccinations. Which of the two resources would you include in your literature review? Why?

• Hviid, Anders, Michael Stellfield, Jan Wohlfart, and Mads Melbye. “Association Between Thimerosal-Containing Vaccine and Autism.” Journal of the American Medical Association 290, no. 13 (October 1, 2003): 1763–1766. http://jama.jamanetwork.com/article.aspx?articleid=197365
• Chepkemoi Maina, Lillian, Simon Karanja, and Janeth Kombich. “Immunization Coverage and Its Determinants among Children Aged 12–23 Months in a Peri-Urban Area of Kenya.” Pan-African Medical Journal 14, no.3 (February 1, 2013). http://www.panafrican-med-journal.com/content/article/14/3/full/

For Education students: Your topic is music therapy in kindergarten classrooms in the United States. Which of the two resources would you include in your literature review? Why?”

• Simpson, Kate, and Deb Keen. “Music Interventions for Children with Autism: Review of the Literature.” Journal of Autism and Developmental Disorders 41, no. 11 (November 2011): 1507-1514.
• Bowman, Robert. “Approaches for Counseling Children Through Music.” Elementary School Guidance and Counseling 21, no. 4 (April 1987): 284-91.

Image attribution

Literature Reviews for Education and Nursing Graduate Students Copyright © by Linda Frederiksen is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.

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Eugene McDermott Library

Literature review.

• Collecting Resources for a Literature Review
• Organizing the Literature Review
• Writing the Literature Review
• Examples of Literature Reviews

Sources for Literature Review Items

Sources for a Literature Review will come from a variety of places, including:

•Books Use the Library Catalog  to see what items McDermott Library has on your topic or if McDermott Library has a specific source you need. The WorldCat   database allows you to search the catalogs on many, many libraries. WorldCat is a good place to find out what books exist on your topic.

•Reference Materials Reference Materials such as encyclopedias and dictionaries provide good overall views of topics and provide keyword hints for searching. Many will include lists of sources to consider for your literature review.

•Journals via Electronic Databases Journals are a major source of materials for a literature review. With the library's databases, you can search thousands of journals back a century or more.   

•Conference Papers At conferences, professionals and scholars explore the latest trends, share new ideas, and present new research. Searching Conference papers allows you to see research before it is published and get a feel for what is going on in a particular organization or within a particular group. 

Many electronic databases include conference proceedings, but with Conference Proceedings Citation Index database, you can search proceedings alone. 

•Dissertations & Theses Here is a link to databases licensed by UTD McDermott library with full-text access to Dissertations and Theses

Some of these are specific to Texas or UTD produced studies. Choose the Global option to search more broadly.

•Internet The general internet can be a valuable resource for information. However, it is largely unregulated. Be sure to critically evaluate internet sources. Look at the Evaluating Websites  LibGuide for suggestions on evaluating websites.

•Government Publications The U.S. government produces a wide variety of information sources, from consumer brochures to congressional reports to large amounts of data to longitudinal studies. For the United States, Usa.gov is a good place to start.  Official state websites can be helpful for individual state statistics and information. 

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• Last Updated: Mar 22, 2024 12:28 PM
• URL: https://libguides.utdallas.edu/literature-review

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