Evidence Synthesis Project Toolkit

There are many types of literature reviews and evidence synthesis projects and they differ from one another in their purpose, scope, methodology, and rigor. In the table below, you'll see just 6 of the most common review types described briefly. For help choosing a review type that fits your goals, resources, and time-frame, see the Review Planning and Protocol tab.

In their landmark typology of review articles, Grant and Booth (2009) described and analyzed 14 common types of reviews. More recently, an expanded exploration of review types identified 48 different review types and grouped them into seven 'families' based on common features (Sutton, et al., 2019).  

Grant, M. J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health information & Libraries Journal, 26(2), 91-108. https://doi.org/10.1111/j.1471-1842.2009.00848

Sutton, A., Clowes, M., Preston, L., & Booth, A. (2019). Meeting the review family: Exploring review types and associated information retrieval requirements. Health Information & Libraries Journal, 36(3), 202-222. https://doi.org/10.1111/hir.12276

Literature Review (aka Narrative Review)

• Looks at literature across a specific topic
• Synthesizes the evidence found 
• Can involve searching one specific database or multiple databases
• Searching is tracked, but need not be systematic or nor comprehensive

Rapid Review

• Knowledge synthesis that aims to produce evidence in a timely manner
• Streamlines or omits certain methods/steps used in a traditional systematic reviews
• Used when quick answers are needed for policy or decision-making, or for emerging research topics
• Requires detailed and rigorous reporting of the review stages and processes

Scoping Review

• Knowledge synthesis that follows a systematic approach with the goal of exploring and mapping the literature on a topic
• Identifies the types of available evidence, clarifies key concepts, theories, and sources
• Identifies knowledge gaps
• Does not typically assess the quality of studies included
• Follows a systematic approach that includes a clearly defined protocol and a structured search process to identify relevant articles

Systematic Review

• Knowledge synthesis that follows a systematic approach with the goal of answering a specific and clearly formulated research question
• Follows a structured approach with a clearly defined protocol, a comprehensive search process, a method for critical appraisal, and a formal process for data extraction and synthesis
• Structured approach allows for transparency and reproducibility

Meta-Analysis 

• A systematic review of quantiative studies that incorporates a statistical technique to combine the results of multiple independent studies on a specific topic to arrive at a more robust and reliable conclusion than an individual study could provide. 
• follows a structured approach with a clearly defined protocol, a comprehensive search process, a method for critical appraisal, and a formal process for data extraction and synthesis

Meta Synthesis or Qualitative Meta-Analysis

• A systematice review of qualitative studies that incorporates techniques to combine the results of multiple independent studies on a specific topic to identify overarching themes, patterns and insights that may not be apparent in an individual study
• Follows a structured approach with a comprehensive search process, a method for critical appraisal, and a formal process for data extraction and synthesis