Subject Guides

Literature Review and Evidence Synthesis

Overview of a Literature Review

A literature review is a generic term used to describe a synthesis of information to answer a research question. The purpose of a literature review is to present the scholarly information that is available on a topic, provide support to the proposed research and relate the literature to the proposed research question. There are numerous types of literature reviews. They vary in complexity and methodology, from a narrative review to systematic review. 

Review types differ by: 

  • The precision of the research question (broad to specific)
  • The goal of the review (background to in-depth inquiry)
  • The standards of the methodology employed (search and reporting methods)
  • If the studies included are appraised 
  • How information from various sources are synthesized
  • The analysis of the results (qualitative or quantitative)
  • The description of the results (broad to specific)

How to Determine the Type of Review

Questions to ask when determining the type of literature review by Cornell University Library

Right Review  This tool assists users to determine which evidence synthesis project is appropriate for their research question. 

Various Types of Reviews

Review Typology Resources:

  • Grant, M. J. & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health information and libraries journal 26(2). https://doi.org/10.1111/j.1471-1842.2009.00848.x
  • Sutton, A., Clowes, M., Preston, L. & Booth, A. (2019). Meeting the review family: Exploring review types and associated information retrieval requirements. Health information and libraries journal. 36(3).  https://doi.org/10.1111/hir.12276
Review Type Definition Search Methods Appraisal Synthesis Analysis
Literature or Narrative Review (May be completed by a single author) Generic term: A synthesis of current literature surrounding a specific topic. The purpose of this review is to provide background information on a topic, support a proposed research project and/or answer a research question.  Non-specific; Author chooses relevant articles based on a research question Determined by author Narrative Chronological, conceptual, thematic, etc. Determined by author and research question
Scoping/Mapping Review (Requires a minimum of 2 authors) Preliminary assessment of potential size and scope of available research literature on a broad topic. Aims to identify the nature and extent of research evidence. Includes grey literature, preprints and ongoing studies. Scoping reviews are conducted according to the JBI manual of evidence synthesis.  Broad scope of literature available. Search methods must be transparent and reproducible. Search strategies for all databases are peer reviewed and documented in full.  All evidence is independently screened by 2 reviewers to ensure the evidence meets the inclusion criteria set within the protocol prior to starting the review.  Narrative Characterizes quantity and quality of literature based upon the elements of the PCC research question and the inclusion/exclusion criteria
Systematic Review (Requires a minimum of 2 authors) Seeks to systematically search for, appraise and synthesize all research evidence on the specific research question posed. SRs are conducted according to the Cochrane or JBI guidelines Exhaustive, comprehensive and systematic search. Search methods must be transparent & reproducible. Search strategies are peer reviewed & well documented.  All evidence is independently screened by 2 reviewers to ensure the evidence meets the inclusion criteria and critically appraised using the JBI Critical Appraisal Checklists Narrative Synthesizes what is known within the existing evidence/literature. Highlights what is unknown & recommends future research
Umbrella Review (Requires a minimum of 2 authors) Reviews the results of multiple systematic reviews on a specific topic. All reviews must analyze a shared methodology, facilitating comparison and analysis. Umbrella reviews are conducted based upon the JBI manual of evidence synthesis Exhaustive, comprehensive & systematic search of reviews. Does not include primary studies. Search methods must be transparent, reproducible and well documented.  All evidence is independently screened by 2 reviewers to meet inclusion criteria and critically appraised using the JBI Critical Appraisal Checklists Graphical and tabular with narrative commentary What is known; Recommendations for practice. What remains unknown; recommendations for future research

Rapid Review

(Requires a minimum of 2 authors)

 Assessment of what is already known about a policy or practice issue, by using systematic review methods to search and critically appraise existing research. RRs are conducted according to the JBI manual of evidence synthesis Completeness of searching determined by time constraints. All search strategies must be transparent, reproducible and well documented. 

Time-limited formal quality assessment.

All evidence is independently screened by 2 reviewers and critically appraised using the JBI Critical Appraisal Checklists

 Narrative and tabular Quantities of literature and overall quality/direction of effect of literature
Meta-analysis

Statistical analysis of quantitative evidence provided within a systematic review. 

Meta-analyses are conducted according to the Cochrane or JBI guidelines

 Exhaustive, comprehensive & systematic search of reviews. Does not include primary studies. Search methods must be transparent, reproducible and documented. All evidence has been critically appraised in the systematic review Graphical representation of the quantitative data in a Forest plot.  Numerical analysis of measures of effect assuming absence of heterogeneity

Reproduced from Grant, M. J. and Booth, A. (2009), A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26: 91–108. doi:10.1111/j.1471-1842.2009.00848.x