How to Write a Literature Review

What a Literature Review Must Do

A literature review is a critical synthesis of existing scholarship that maps the terrain of a research area, identifies what is known and contested, and — in its most important function — establishes the intellectual gap that your research fills. It is not a catalogue of what others have said; it is an argument about what the field does and does not yet understand.

A well-constructed literature review accomplishes four things simultaneously:

1. Demonstrates your command of the field and its key debates
2. Positions your work within an existing scholarly conversation
3. Justifies your theoretical framework and methodological choices
4. Establishes the gap or problem your research addresses

Review Types

Systematic Review Methodology

A systematic review is defined by methodological rigour and reproducibility. Its core requirement is that the search and selection process is transparent enough to be repeated by another researcher. Key components:

• Protocol registration — systematic reviews should be registered on PROSPERO (health sciences) or OSF (social sciences) before data collection begins
• Explicit inclusion/exclusion criteria — defined before searching, covering publication date, language, study design, population, and setting
• Multiple database searching — at minimum two or three major databases (e.g., MEDLINE + CINAHL + PsycINFO for health; Web of Science + Scopus + SSRN for social sciences)
• Dual-reviewer screening — title/abstract and full-text screening conducted by two independent reviewers; disagreements resolved through discussion or third-party arbitration
• Quality appraisal — using validated tools (CASP checklists, Newcastle-Ottawa Scale, GRADE framework)

PRISMA Protocol

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) provides a standardised framework for reporting the search and selection process. The PRISMA flowchart is now required by most health and social science journals for systematic reviews.

Boolean Search Strategy

A robust search strategy uses Boolean operators to combine search terms systematically across databases:

• AND — narrows the search (both terms must appear): resilience AND adolescents
• OR — broadens the search (either term may appear): resilience OR psychological hardiness OR stress resistance
• NOT — excludes terms: resilience NOT ecological NOT engineering
• Truncation (*) — retrieves all word endings: adolescen* finds adolescent, adolescents, adolescence
• Phrase searching ("") — matches exact phrases: "academic achievement"
• Wildcards (?) — replaces single characters: wom?n finds woman, women

Critical Reading at Scale

A literature review for a dissertation may require reading 60–150 sources. A three-pass system manages this efficiently:

1. Pass 1 — triage: Read title, abstract, and conclusion (3–4 minutes). Decide: include, exclude, or uncertain. Assign to reading priority tier.
2. Pass 2 — extraction: For included sources, extract: theoretical framework, methodology, sample, key findings, limitations. Record in a synthesis matrix.
3. Pass 3 — deep reading: For the 15–25 sources central to your argument, read in full with critical annotations. Note: what does this claim? Is the evidence adequate? What assumptions does it make?

The Synthesis Matrix

A synthesis matrix is a table with sources as rows and analytical dimensions as columns. It transforms individual notes into a visual map of the field, revealing patterns, agreements, contradictions, and gaps that are invisible when reading source by source.

Once populated, the matrix reveals: which theoretical frameworks dominate, which are absent; where geographic or demographic gaps exist; which claims are replicated and which rest on a single study.

Organising Principles

The two main organising principles for literature reviews are thematic and chronological. Thematic organisation is strongly preferred at graduate and doctoral level:

• Thematic: Groups sources by conceptual similarity — each section addresses a facet of the research question. More analytical; allows genuine synthesis across authors and periods.
• Chronological: Traces the development of a field over time. Useful when intellectual history is the argument; often degenerates into annotated bibliography if not carefully structured.
• Methodological: Groups studies by method type. Used in systematic reviews where comparing evidence quality across methods is the purpose.

Writing the Synthesis

Each paragraph of a synthesised literature review should make a claim about the field — not describe a source. The structure is: claim → evidence from multiple sources → analysis of what the evidence reveals.

Common Literature Review Failures