What Is a Literature Review? Types, Purpose and Steps
Published 28 Apr 2025 · Updated 9 Oct 2026
What is a literature review? It is a critical account of published research on a topic: what is known, where researchers disagree and what is still missing. This guide covers the purpose, the main types and a step-by-step method, with a worked example of a weak and a strong paragraph.
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What is a literature review?
A literature review gathers the main sources on a topic and discusses them together. You group the findings, compare them and judge their quality. Then you say what the evidence adds up to. The word 'literature' means scholarly sources, such as journal articles, academic books, official reports and conference papers.
You will meet literature reviews in three places.
- A short section inside an essay or report
- A chapter of a dissertation or thesis, leading into your research question
- A stand-alone assignment or a published paper
Literature review definition
In one line: a literature review is a synthesis of existing scholarship that leads to a point. Librarians at Falmouth University put it as a survey and synthesis of existing scholarly work. They add that it is not a summary of texts one after another.
Synthesis, not summary
Summary says what each source found. Synthesis shows how sources relate: where they agree, where they conflict and why. Purdue OWL gives a handy clue. A paragraph that cites several sources is usually synthesising. A paragraph built around one source is usually summarising.
Subject habits differ
Humanities reviews often argue about how sources interpret an idea. Science reviews more often report study designs and results. Read a few reviews from your own subject and copy their conventions, not their wording.
Purpose of a literature review
A review does several jobs at once. Markers look for most of these.
- It shows you know the key ideas, debates and authors in the field
- It spots a gap, a conflict or a weakness that your own question can address
- It helps you choose a framework or method by showing what others used
- It places your work in the wider conversation, so readers see why it matters
- It saves you from repeating work that has already been done
Types of literature review
Your module decides which type you need. The table shows the common ones. Most undergraduate essays and dissertations expect a narrative review.
| Type | What it does | Where you may meet it |
|---|---|---|
| Narrative | Summarises, compares and critiques research on a topic. Source choice rests on your judgement. | Essays and dissertation chapters |
| Systematic | Follows a planned, documented method to find and appraise all relevant studies on a focused question. | Health and social science projects |
| Scoping | Maps how much research exists on a broad topic and where the gaps are. | Early-stage projects and funding bids |
| Integrative | Combines different kinds of evidence into one picture. | Nursing and education |
| Critical | Evaluates the literature in depth and may propose a new way of seeing the topic. | Postgraduate work |
If your brief says 'systematic'
You will need a written search plan, rules for including and excluding studies and a record of how many sources you screened. Ask your supervisor what reporting guidance your department follows before you start searching.
If your brief just says 'review the literature'
Write a narrative review. Define your question, choose a clear organising idea and keep the search notes you used, in case your marker asks how you found your sources.
Review or annotated bibliography?
| Annotated bibliography | Literature review | |
|---|---|---|
| Shape | A list of sources, each with a short note | A connected argument built from sources |
| Order | Alphabetical or by date | By theme, method, theory or time |
| Main skill | Summarising and evaluating one source | Comparing sources and drawing a conclusion |
Notes taken for an annotated bibliography are a good start. You then regroup them by idea, which is where the analysis happens.
How to write a literature review
Work through these steps in order, and return to earlier ones as you learn more.
- Write your question in one sentence
- Set the scope: dates, countries, groups of people and types of study
- Search library databases with keyword combinations, then follow the reference lists of key papers
- Read abstracts first, then the full text of the best matches
- Record the aim, method, findings and limits of every source
- Sort sources into themes, debates or methods
- Draft one theme at a time, then revise so the whole review builds to your gap
Choose how to organise it
Purdue OWL lists four common patterns: chronological, thematic, methodological and theoretical. Thematic suits most student reviews. For a model outline, see our guide to literature review structure.
Keep your references tidy from day one
Store each source in a reference manager or a spreadsheet as you find it. Our APA citation generator and Harvard referencing generator format the entries once you have the details.
Literature review example
This invented example reviews research on spaced revision and exam results. The sources are placeholders, so you can see the pattern without a real citation to copy.
| Version | Paragraph |
|---|---|
| Weak (summary) | [Author A, year] studied revision timetables in one school. [Author B, year] ran a similar study in a college. [Author C, year] surveyed students about revision habits. |
| Strong (synthesis) | Two controlled studies [Author A, year; Author B, year] link spaced revision to higher exam scores, but both used small samples. A survey [Author C, year] found the same pattern, yet it relied on students' own reports. The evidence is consistent but thin, and none of it covers adult learners. |
The strong version names a pattern, notes a weakness in the method and ends on a gap. That gap is what your own question can fill.
Checklist before you submit
- Does each paragraph make a point, not just report a source?
- Have you included studies that disagree with your view?
- Do you comment on sample size, method and date where it matters?
- Does the review end by stating the gap or question?
- Are all in-text citations in your reference list, in one style?
Common mistakes
- Listing sources one by one in the order you read them
- Using only sources that support your view
- Quoting too much instead of putting findings in your own words
- Relying on blogs when peer-reviewed work exists
- Leaving out the link to your research question
Need feedback on your review?
Our specialists comment on your draft's structure, balance and referencing, and you write the final version yourself. See how it works or ask about dissertation editing for a full chapter. To plan the whole project, try the dissertation outline generator.
Related guides
- Literature review structure
- Data collection methods
- Dissertation structure
- Dissertation outline generator
Sources
- Falmouth University Library, Literature reviews: about
- Purdue Online Writing Lab, Writing a literature review
- University of Illinois Library, Types of reviews
Frequently asked questions
What is the purpose of a literature review?
To show what is already known, judge the quality of that knowledge and point to the gap your own work addresses.
Is a literature review the same as a systematic review?
No. A systematic review is one type, with a planned and documented search method. Many student reviews are narrative.
How many sources should I use?
It depends on your level, topic and word count. Your module handbook may give guidance. Choose relevant, good-quality sources over a large number.
Do I include my own opinion?
Reach your own conclusions, but base them on the evidence in the sources. Personal views without support will not earn marks.
What is the difference between a literature review and an annotated bibliography?
An annotated bibliography lists sources with notes. A literature review links them into one argument.
How long should a literature review be?
It varies from a few paragraphs in an essay to a full chapter in a dissertation. Follow your brief.
Can a literature review be a whole dissertation?
In some courses, yes. Ask your department, because rules differ.