Literature Review

Say what the review covers and why it matters now. State the question or topic, and draw the boundaries: which years, which kinds of study, which populations or fields. In a thesis chapter, connect it to your research question from the start. Give a short preview of how the review is organized.

Explain how you searched. For a narrative review this can be brief: the main databases, the search terms, and how you chose what to include. It’s optional in many courses, but it lets readers judge what you might have missed.

For a systematic review it’s the core of the methods. PRISMA 2020 asks authors to list every database, register and website searched, with the date each was last searched; to give the full search strategy, filters included; to state the eligibility criteria; and to describe how studies were screened and how their risk of bias was assessed. A flow diagram shows how the records found were narrowed down to the studies finally included. Many systematic reviews also publish or register a protocol in advance, for example on PROSPERO, so that any later change to the methods is visible.

This is where the work is. Group the literature so the reader sees the shape of the field, not a queue of papers. Common ways to organize:

• By theme: each section covers one question, factor or finding, and draws on every study relevant to it.
• By debate: set out the positions, the evidence for each, and where the disagreement really lies.
• By method: compare what experiments, surveys, case studies or models have each shown, useful when the method shapes the answer.
• By chronology: trace how understanding changed, built around turning points rather than a year-by-year list.
• By theory: compare the frameworks and definitions researchers use, often the setup for a thesis’s own framework.

Many reviews combine these, such as themes within a broadly chronological account. Within each section, synthesize: say what the studies show together, where they agree, why they might differ, and how strong the evidence is. A paragraph built on a single source is usually a sign of summary, not synthesis.

Say what the literature doesn’t yet answer. A gap is rarely a topic no one has touched. More often it’s a population or place not yet studied, a method not yet applied, a theory not yet tested, or findings that are old or few. In a thesis, the gap you name here is the one your research fills.

Sum up what’s known, how confident the field can be, and what’s still open. For a thesis chapter, end by leading into your own question and methods. For a review article, end with what it means for research and, where relevant, for practice.

Every work you discuss, in the required style. In a review the reference list is often long, and readers use it as a map of the field. Get every entry right.