What Is a Literature Review?

Most students start their literature review before they understand what exactly this part of the research process needs to achieve. They read for months, then write a chapter that works through their sources one at a time, and it comes back marked “not critical enough”. The reading was fine. The chapter wasn’t.

We’ve helped 10,000+ students with their dissertations and theses, and “not critical enough” is one of the most common comments we see on a literature review. In this post, I’ll explain what a literature review is, what it’s for and what a good one looks like, using a real-world example from a distinction-grade dissertation, written two ways.

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What is a literature review?

A literature review is an organized, critical account of the existing research on a topic: what’s already known, where researchers disagree, and what hasn’t been studied yet. In a dissertation or thesis, it also shows where your own study fits into that picture.

The term gets used for three related things, which is part of why it confuses people:

• The process. Finding, reading and judging the research already out there on your topic, and keeping organized notes as you go, ideally in a literature review spreadsheet.
• The chapter. The write-up of what you found, usually Chapter 2 in a standard dissertation structure. This is what your committee (examiners, in the UK) actually reads and grades.
• A standalone piece. Some courses set a literature review as an assignment in its own right, and journals publish review articles that do nothing else. The ideas are the same; there’s just no study of your own at the end.

The first two overlap more than the names suggest. You’ll keep reading while you write, and the writing will show you what you haven’t read yet. From here on, “literature review” mostly means the chapter, because that’s where the marks are.

Here are the three meanings side by side. Look at the two arrows between the process and the chapter:

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“Literature” here means research written up for other researchers, the kind you’ll find in academic databases. That’s mostly peer-reviewed journal articles, plus academic books, theses and dissertations, and sometimes reports from governments or industry bodies (often called gray literature).

Even researchers who classify reviews for a living admit the term is loose. One widely cited paper that sorts reviews into types calls the standard library-catalog definition “necessarily a very broad description”, then sets out what most literature reviews have in common:

Notice the four verbs: identify, select, synthesize and analyze. Most students do the first two well. However, it’s the last two, pulling the sources together and judging what they’re worth, that turn a reading list into a review, and they’re what the rest of this post is about.

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What’s the purpose of a literature review?

Your literature review isn’t there to prove you did the reading. It has four jobs, and each one feeds a later part of your dissertation:

1. Show that you know the field. Who has studied your topic, what they found, where they agree and where they don’t. Your reader should finish the chapter trusting that you know the ground better than they do.
2. Reveal the gap your study fills. By showing what’s known, you show what isn’t. That research gap is the justification for your study, so the chapter should lead the reader to it step by step, not just state it.
3. Ground your conceptual framework. If your study tests how a set of factors relates to an outcome, those factors need to come from the literature, not from your own assumptions. Say you’re studying why newly qualified nurses leave their first job: the review is where workload, support or pay earn their place in your conceptual framework.
4. Inform your methodology. The studies closest to yours show you which research designs, samples and measures have worked, and which haven’t. Quantitative researchers can often borrow a validated scale outright rather than build one.

These jobs build on each other. Knowing the field is what lets you see the gap. The gap tells you what your framework has to explain. And the studies you’ve read show you how others went about measuring those things, which is a head start on your methodology chapter.

So when you plan your review, check every section against these four jobs. A section that does none of them is usually background you can cut.

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What does a literature review look like?

This is where most first drafts go wrong: they summarize their sources when they should synthesize them. The University of North Carolina’s Writing Center puts the difference in one sentence:

Here’s that difference as a picture, with the same three sources on both sides. Notice that Source B feeds two ideas on the synthesis side, and that only the synthesis side ends on a point about your study:

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You’ll still summarize a little, because your reader needs to know what each source found, but synthesis is what earns the marks. It’s easiest to see on a real passage.

The passage comes from the literature review of an MBA dissertation that was awarded a distinction, a study of what makes customers trust a company they only ever deal with online. It discusses one idea, distrust, using three sources. You’ll see it twice. The first version is one I wrote for this post, to show how a typical first draft handles sources like these: same three citations, same claims, but each source gets its own sentence and nothing connects them. The second is what the student actually submitted, with their industry replaced by [industry] and their UK spelling kept.

One term to know first: “domain-specific” trust is trust about one particular task (handling your money, say), while “domain-agnostic” trust is trust in someone in general.

Each sentence is cited and accurate. But read it again and ask what the author thinks. You can’t tell, because the passage never says how the three sources relate, or why any of it matters to this study.

Now the passage as it was actually submitted:

Look at what the submitted version does with the same three sources:

• The author takes a position. “Relating this distinction to the [industry] context, it is plausible that…” is the author’s own judgment, applied to the study’s setting. The summary version has no author in it at all.
• It leads somewhere. The passage’s closing paragraph turns the debate into a decision about the study’s scope, so the reader knows why the section was there.
• The order is an argument. “However… challenged this theory” and “disputed this view” put each source in reply to the one before, so the three read as a debate rather than a list.

The sources still appear one after another, as they did in the summary version. What makes it synthesis is that they’re arranged around one question (can trust and distrust co-exist?), not around who said what.

So, in practice: after each cluster of sources, ask what they add up to, and write that sentence. Doing that consistently is most of what synthesizing the literature means.

To see the whole chapter this passage comes from, watch the walkthrough below, or read four annotated sections from it, with what each part does well.

What a literature review is not

A lot of weak chapters are really one of these four things wearing a literature review’s title:

• An annotated bibliography. As UNC’s Writing Center puts it, a literature review is “usually organized around ideas, not the sources themselves as an annotated bibliography would be organized.” One source per paragraph is the clearest sign.
• Everything you read. You’ll read far more than you cite. Every source in the chapter should earn its place by helping one of the four jobs above.
• Your reaction to the sources. Whether you liked a source isn’t critique. Being critical means weighing the evidence: sample sizes, settings, methods, contradictions. Judgment belongs in the chapter; preference doesn’t.
• A one-off task. You’ll come back to the literature in your discussion chapter, where your findings are compared with the studies you reviewed. Keep your notes organized for that.

If your draft looks like any of these, you’re not alone: the first two are among the most common literature review mistakes we see. The fix is usually to restructure, not to read more. I’d start by regrouping your sources by idea, then rewriting each section’s opening so it makes a claim.

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Where it sits in your dissertation

In most dissertations and theses, the literature review is Chapter 2, between the introduction and the methodology. The introduction says what you’re studying and why. The literature review sets out what’s already known. The methodology then explains how you’ll add to it.

That’s the common layout, not the only one. Some programs fold part of the review into the introduction, and in a thesis made up of published papers, each paper usually carries its own shorter review. Your research proposal will have a condensed version too. Check your program’s handbook for the layout it expects.

Inside the chapter, there’s no single correct structure. Most reviews are organized by theme, by time or by research method, and many combine them. Whichever you choose, start broad and narrow toward your research questions, so the chapter ends close to your gap.

Types of literature review

“Literature review” is also the name of a whole family of review types, and the differences matter if you’re asked which kind you did. Grant and Booth’s typology describes fourteen. The table paraphrases their descriptions of the six you’re most likely to meet:

Type	What it does
Literature review (what we’d call a narrative review)	Examines recent or current literature on a topic, at varying levels of completeness. Searching and appraisal methods vary
Critical review	Goes beyond describing the literature to evaluate its quality, and typically ends in a hypothesis or model
Systematic review	Systematically searches for, appraises and synthesizes research evidence, often following published guidelines such as Cochrane’s, and reports its methods so others can repeat them
Systematized review	Uses some elements of a systematic review without claiming to be one. Grant and Booth note it’s typically done as a postgraduate assignment
Scoping review	Gives a preliminary assessment of how much research exists on a topic, and of what kind
Meta-analysis	Statistically combines the results of quantitative studies to give a more precise estimate of an effect

Most of the dissertation and thesis chapters we see are the first kind, a narrative literature review. If you searched databases with a fixed strategy and recorded what you found, but skipped some steps of a full systematic review (formal quality appraisal, for example), call it “systematized”. “Systematic” implies you did every step. And if your whole dissertation is a review (some programs allow a systematic or scoping review as the project itself), your methodology chapter will need to follow the guidelines for that type.

Don’t worry if your review doesn’t sit neatly in one row. Grant and Booth themselves note that the types overlap: “many fall short of being mutually exclusive”. What matters is that you name your approach accurately and describe how you found and selected your sources.

Still have questions?

What are the 5 C’s of a literature review?

The 5 C’s are a literature review checklist that Texas Tech’s Graduate Writing Center teaches: cite, compare, contrast, critique and connect. You cite the sources you draw on, compare what they share, contrast where they differ, critique how well each study was done, and connect the whole picture to your own research. It’s a useful self-check on a draft, because a section that only does the first C is a summary.

Can ChatGPT write my literature review?

AI tools can help you find and organize sources, but writing the chapter with one is risky. In one 2023 study, researchers asked GPT-3.5 and GPT-4, the models behind ChatGPT, to write short literature reviews on 42 topics. Of the citations, 55% from GPT-3.5 and 18% from GPT-4 were fabricated. Newer tools may do better, but the critique still has to come from you.

Many universities treat it as misconduct to submit AI-generated text as your own, and policies on AI as a research aid vary, so check yours before you start.

How long should a literature review be?

It depends on your program and the size of the project. As a rule of thumb, our coaches often start from about 20 to 30% of a dissertation’s total word count for the literature review, then adjust to suit the project. A doctoral review is usually much longer than a master’s one. Your program’s handbook or your advisor’s guidance overrides any rule of thumb.

Is a literature review the same as a systematic review?

No. A systematic review is one specific type of literature review, with a formal protocol for searching, screening and appraising studies, and methods reported so that others can repeat them. Most dissertation literature reviews are narrative reviews: still careful and critical, but without that full protocol. If your review used some systematic steps but not all, “systematized review” is the more accurate label.

How is it different from an annotated bibliography?

An annotated bibliography lists sources one at a time, each with a short summary and often a note on its quality or relevance. A literature review is organized around ideas instead, and shows how the sources relate to each other and to your question. Many students keep an annotated bibliography while they read, then rework it into a review when they write.

What should a literature review include?

A literature review usually includes an introduction that sets out its scope and structure, a body that discusses the literature by theme, time or method, and a conclusion that pulls the findings together and leads to your research gap. Along the way, it should cover the main theories in your area and the key empirical studies. What matters most is that the body synthesizes the sources rather than summarizing them one by one.

How does a literature review differ from a critique?

A critique evaluates one work in depth: its argument, methods and conclusions. A literature review evaluates a whole body of research and shows how the studies relate to each other and to your question. A good literature review contains a lot of critique, but it uses it to build an argument across many sources, rather than to assess any single one.

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Cite-worthy sources

Cite this article

Jansen, D. & Warren, K. (2020). What Is a Literature Review?. Grad Coach. https://gradcoach.com/what-is-a-literature-review/

Copy citationMore citation formats

• Grant, M. J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26(2), 91-108.
• Hair, B. (n.d.). 5 Cs to writing a literature review. Texas Tech University Graduate Writing Center.
• The Writing Center. (n.d.). Literature reviews. University of North Carolina at Chapel Hill.
• Walters, W. H., & Wilder, E. I. (2023). Fabrication and errors in the bibliographic citations generated by ChatGPT. Scientific Reports, 13, 14045.