Skip to main content
LibApps staff login

Evidence Synthesis in the Social Sciences

This guide links resources, tools, scholarly articles, and other information to support those conducting and assisting with evidence synthesis in the social sciences.

Common Types of Evidence Synthesis

Systematic Reviews

Systematic reviews are the most well-established evidence synthesis method, with many standards and guidance documents available. They may be quantitative and include a meta-analysis (a statistical combination of results across studies), but not all systematic reviews include a meta-analysis. 

Scoping Reviews

Scoping reviews are often used to determine the extent and size of available research literature. They address broader questions than systematic reviews and can be useful research products or serve as a precursor to a systematic review. Critical appraisal is typically not part of the scoping review process. (Critical appraisal is the process of carefully examining research to judge its reliability, value and relevance within a specific context.)  

Systematic Maps, Mapping Reviews, and Evidence and Gap Maps

One family of evidence synthesis is systematic maps, mapping reviews, and evidence gap maps (EGMs). These reviews aim to catalog and describe the existing evidence on a particular topic. These tend to be broader in scope than a systematic review and can be used to identify areas of knowledge saturation and knowledge gaps. The results of these types of reviews may be presented as a thematic matrix, indicating studies that address specific intervention types and outcomes, or other visualizations that aid the reader in exploring the available evidence on the topic.

Rapid Reviews

Rapid reviews and related methods, such as rapid evidence assessments, gather and synthesize available research evidence in a shorter timeframe than a systematic review, typically within six weeks to six months. Rapid reviews employ many of the same systematic methods but expedite steps by taking shortcuts or focusing on a more narrowly defined scope. Rapid reviews should not be used to shorten the time commitment for conducting a review, but rather should be well justified and related to a timely practice or policy need for evidence-based decision-making.

Umbrella Reviews

Umbrella reviews are systematic reviews that include other systematic reviews or meta-analyses as their components. These are also sometimes referred to as reviews of reviews, overviews of reviews, or meta-reviews. Umbrella reviews are conducted when many systematic reviews have already been published on a topic.

Living Systematic Reviews

Living systematic reviews aim to provide a process for regularly updating a systematic review, as a systematic review can quickly become outdated in rapidly evolving research fields. Living systematic reviews may employ various forms of automation or be published in a format outside of the peer-reviewed journal, which provides an easier platform for updates and changes.

Recommended Article: 

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

Which Review Type is Right For You?

Your review type should match your intended purpose. 

You can also use Right Review, which provides guidance and supporting materials on methods for conducting and reporting knowledge synthesis.

Recommended Article: Stuart, D., & Kennedy, K. (2024). Right Review: A Web-Based Tool for Review-Based Research. Journal of Electronic Resources in Medical Libraries, 1–8. http://doi.org/10.1080/15424065.2024.2423942

Flowchart illustrating decision-making for selecting a type of research review.

Image credit: "What Type of Review is Right for You?" Cornell University Library.

Text description of the flowchart graphic above:

  1. Starting question: Do you want to gather all the evidence on a particular research topic?

    If yes, proceed to Step 2.

    If no, conduct a Literature (Narrative) Review.

  2. Step 2, question: Do you have 3 or more people to work on the review?

    If yes, proceed to Step 3.

    If no, more intensive reviews usually require a multi-person team for unbiased article screening.

  3. Step 3, question: Do you have 12–18 months to complete a review?

    If yes, proceed to Step 4.

    If no, conduct a Rapid Review.

  4. Step 4, question: Do you have a broad topic or multiple research questions?

    If yes, conduct a Scoping Review

    If no, proceed to step 5.

  5. Step 5, question: Do you want to review other published systematic reviews on your topic?

    If yes, conduct an Umbrella Review.

    If no, proceed to step 6.

  6. Step 6, question: Do you have a well-formulated research question?

    If yes, conduct a Systematic Review and proceed to step 7.

    If no, Systematic Reviews are conducted in an unbiased, reproducible way to provide evidence for practice and policy-making and to identify gaps in research. They require a well-formulated research question.

  7. Step 7, question: Will you use statistical methods to objectively evaluate, synthesize, and summarize results?

    If yes, conduct a Meta-Analysis.

    If no, a meta-analysis will not be needed.