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Evidence Synthesis

Explore this guide of curated library and web resources for those working on systematic reviews and other evidence synthesis projects.


This guide is intended to provide general information and resources related to evidence synthesis projects, including systematic reviews, meta-analyses, and other types of reviews. Note that this is not an exhaustive guide nor does it capture the entirety of the rigorous methodologies utilized in these types of projects. We encourage you to contact your liaison librarian when embarking on this kind of research.

Students: Are You Conducting a Review Using Systematic Methods?

Are you an undergraduate or graduate student conducting a high-level literature review for an capstone project, thesis, or other work? We strongly recommend reviewing these student-specific guides to projects that are similar to systematic reviews, but rely on shorter timelines or searching and screening by a single person:

This planning worksheet created by librarians from Cornell University can help describe the steps you should take to conduct your review in a systematic way:

What is evidence synthesis?

According to the Royal Society, evidence synthesis is "the process of bringing together information from a range of sources and disciplines to inform debates and decisions on specific issues" (Royal Society, 2018). These differ from traditional literature or narrative reviews in that they include a comprehensive and reproducible synthesis of research on a topic. Popular forms of evidence synthesis projects include systematic reviews, scoping reviews, and meta-analyses. 

One commonly used form of evidence synthesis is a systematic review.  This table compares a traditional literature review with a systematic review.


Traditional Literature Review

Systematic Review

Review Question/Topic

Topics may be broad in scope; the goal of the review may be to place one's own research within the existing body of knowledge, or to gather information that supports a particular viewpoint.

Starts with a well-defined research question to be answered by the review. Reviews are conducted with the aim of finding all existing evidence in an unbiased, transparent, and reproducible way.

Searching for Studies

Searches may be ad hoc and based on what the author is already familiar with. Searches are not exhaustive or fully comprehensive.

Attempts are made to find all existing published and unpublished literature on the research question. The process is well-documented and reported.

Study Selection

Often lack clear reasons for why studies were included or excluded from the review.

Reasons for including or excluding studies are explicit and informed by the research question.

Assessing the Quality of Included Studies

Often do not consider study quality or potential biases in study design.

Systematically assesses risk of bias of individual studies and overall quality of the evidence, including sources of heterogeneity between study results.

Synthesis of Existing Research

Conclusions are more qualitative and may not be based on study quality.

Bases conclusion on quality of the studies and provide recommendations for practice or to address knowledge gaps.

Types of Reviews

Evidence synthesis projects can be very time intensive, depending on the rigor of the review method selected. Explore the resources below to determine what type of review may be best suited to your research question.

Explore Existing Reviews

Searching for existing reviews on a topic related to your own research question can be a good place to start. These reviews may provide a model for approaching your own review of the literature, including recommended search strategies and resources.