How-to · Step-by-step
How to write a literature review
Writing a literature review means systematically finding, appraising and synthesising the existing research on a topic, then presenting it as a structured, critical argument rather than a list of summaries.
The step most authors miss
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Step by step
How to do it
1.Define the scope and question
Frame a clear, answerable question and set its boundaries — population, concepts, timeframe and disciplines. A structured frame such as PICO (Population, Intervention, Comparison, Outcome) sharpens an empirical question and exposes the concepts you will need to search for.
2.Develop and run a search strategy
Translate each concept into keywords and subject headings, combine them with Boolean operators, and run the search across several relevant databases. Record the databases, terms and dates so the search can be reproduced.
3.Select sources against explicit criteria
Set inclusion and exclusion criteria in advance, then screen titles, abstracts and full texts against them. Pre-specifying eligibility keeps selection consistent and guards against cherry-picking studies that suit your argument.
4.Appraise the quality of what you keep
Read critically and judge each study’s validity, results and relevance, using a structured tool such as a CASP checklist where appropriate. Weight your conclusions toward the more robust evidence.
5.Synthesise the findings by theme
Organise the literature around themes, concepts or debates rather than one paragraph per paper. A concept matrix or summary table helps you group studies, compare findings and surface the gaps your own work will address.
6.Write a structured, critical narrative
Build an introduction, a thematically organised body and a conclusion that states what is known, what is contested and what is missing. Compare and evaluate sources; never merely describe them one after another.
7.Reference accurately and completely
Cite every source in a consistent style and keep a complete reference list. Reference-management software helps maintain accuracy and lets you regenerate citations if the style changes.
A review is an argument, not a list
A literature review is a critical, structured account of what is already known about a topic and where the gaps lie — not a sequence of article summaries. Its purpose is to situate your own work within the existing evidence, identify themes and tensions across studies, and justify the questions you go on to ask. The defining quality of a good review is synthesis: drawing connections across sources so the reader sees the shape of the field. Whether the review stands alone or forms a thesis chapter, the same disciplined process of search, appraisal and synthesis applies.
Narrative, systematic and the spectrum between
How rigidly you follow the steps below depends on the type of review. A narrative review surveys a field selectively and flexibly. A systematic review applies an exhaustive, pre-specified and reproducible protocol, typically reported against the PRISMA 2020 statement, and is the standard for evidence synthesis in health and social care. Scoping, rapid and integrative reviews sit in between. Decide early which type fits your aim and resources, because it governs how comprehensive your search and how formal your appraisal must be.
Common questions
FAQ
How is a literature review different from an essay or a summary?+
A literature review analyses and synthesises a body of research rather than arguing a single thesis from scratch or summarising one text. Its job is to map what is known, compare findings across studies, evaluate their quality and expose gaps. A summary describes one source; a review draws connections across many and uses them to justify a research direction.
Should I organise a literature review by theme or chronologically?+
Thematic organisation is usually stronger because it groups studies by concept or debate, making patterns and disagreements visible. Chronological organisation suits reviews tracing how thinking on a topic has developed over time. Many reviews combine the two — thematic overall, with chronological ordering inside a theme where the history matters.
How many sources should a literature review include?+
There is no fixed number — it depends on the review type, the breadth of the question and how much has been published. A systematic review aims to capture all eligible studies, so the count follows the evidence. A narrative or student review covers the key and representative works. Relevance and quality matter more than a target tally.
