Deciding on a synthesis methodology

Given the variety of evidence synthesis methodologies, it is not always easy to determine which methodology is best for your research project. Luckily, folks in the evidence synthesis community have built tools to help in this process.

Dr. Andrea Tricco and the Knowledge Translation Program developed the Right Review tool, which is designed to provide guidance and supporting material to reviewers on methods for the conduct and reporting of evidence synthesis.

In addition, folks at Cornell University Libraries developed a decision tree for evidence synthesis methodologies.

Please don't hesitate to reach out if you would appreciate personalized help in determining which will be the best fit for your needs and goals.

Common forms of evidence synthesis

Literature Review:

  • "Generic term: published materials that provide examination of recent or current literature. Can cover wide range of subjects at various levels of completeness and comprehensiveness. May include research findings map" (Grant, 2009)

Systematic Review:

  • According to the Cochrane Handbook, "systematic reviews seek to collate evidence that fits pre-specified eligibility criteria in order to answer a specific research question. They aim to minimize bias by using explicit, systematic methods documented in advance with a protocol".

Rapid Review:

  • "A form of knowledge synthesis in which components of the systematic review process are simplified or omitted to produce information in a timely manner" (Tricco, 2015). Rapid reviews first emerged as a tool for health policy decision-makers.

Mixed Methods Review:

  • "Mixed methods reviews can be identified as reviews that incorporate mixed methods primary studies or, more commonly, as reviews that seek to integrate mixed (quantitative and qualitative) data" (Sutton, 2019).

Qualitative Systematic Review:

  • Review of qualitative research. Such reviews may be aggregative or interpretive. "For aggregative reviews, the literature search resembles its quantitative counterpart in systematically exploring a large number of databases and supplementary sources, contrasting with interpretive reviews where theoretical sampling may be appropriate" (Booth, 2016). Qualitative systematic reviews may follow a number of different methodologies: meta-ethnography, content analysis, framework synthesis, etc (Sutton, 2019).

Scoping Review:

  • "Preliminary assessment of potential size and scope of available research literature. Aims to identify nature and extent of research evidence (usually including ongoing research)" (Grant, 2009)

Umbrella Review: 

  • Essentially, a systematic review of systematic reviews. "Specifically refers to review compiling evidence from multiple reviews into one accessible and usable document. Focuses on broad condition or problem for which there are competing interventions and highlights reviews that address these interventions and their results" (Grant, 2009)

Realist Review:

  • A form of evidence synthesis designed for complex policy interventions. "Answers the question “What works for whom under what circumstances?” rather than “What works?”. Specifically, it seeks to unpack the mechanism of how complex programmes work (or why they fail) in particular contexts and settings" (Booth, 2016).

Integrative Review:

  • A well-done integrative review is conducted with the same rigor as a systematic review and is one of the broadest types of research review methods.  Integrative reviews allow for the “simultaneous inclusion of experimental and non-experimental research in order to more fully understand a phenomenon of concern. Integrated reviews may also combine data from the theoretical as well as empirical literature. In addition, integrative reviews incorporate a wide range of purposes: to define concepts, to review theories, to review evidence, and to analyze methodological issues of a particular topic” (Broome, 1993).

Systematized Review:

  • "Systematized reviews attempt to include one or more elements of the systematic review process while stopping short of claiming that the resultant output is a systematic review. Systematized reviews are typically conducted as a postgraduate student assignment, in recognition that they are not able to draw upon the resources required for a full systematic review (such as two reviewers)." (Grant, 2009)


Booth, A. (2016). Searching for qualitative research for inclusion in systematic reviews: A structured methodological review. Systematic Reviews, 5, 74.

Broome, M.E., (1993). Integrative literature reviews for the development of concepts. In B.L. Rodgers & K.A. Knafl (Eds.), Concept Development in Nursing (231-250), (2nd ed.). Philadelphia: W.B. Saunders Co.

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), 91–108.

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.

Tricco, A. C., Antony, J., Zarin, W., Strifler, L., Ghassemi, M., Ivory, J., Perrier, L., Hutton, B., Moher, D., & Straus, S. E. (2015). A scoping review of rapid review methods. BMC Medicine, 13(1), 1–15.