Much of this guide has been adapted with permission from Cornell University Library's A Guide to Evidence Synthesis (2025). We are grateful to the librarians at Cornell for their generosity in sharing their work with us.
River Campus/Non-Health Sciences Researchers
This guide focuses on systematic reviews and other types of evidence synthesis outside the health sciences (e.g., the social sciences and STEM) and is intended primarily for faculty and students on the University of Rochester River Campus.
URMC/Health Sciences Researchers
For information about and assistance with health sciences evidence synthesis projects at the UR Medical Center, please see Miner Library's guide to systematic reviews:
Evidence synthesis is a research method that utilizes information from multiple studies on the same topic to provide a comprehensive view of the research in that specific area. Common types of evidence synthesis include systematic reviews, scoping reviews, meta-analyses, and more. (See below for brief descriptions of some common types of evidence syntheses.)
Systematic reviews are the most common type of evidence synthesis. According to the Campbell Collaboration (2021), "a systematic review summarizes the best available evidence on a specific question using transparent procedures to locate, evaluate, and integrate the findings of relevant research." Once the purview of the health sciences, evidence synthesis projects are becoming more common in the social sciences and, to a lesser degree, the humanities.
Evidence syntheses are much more time-intensive than traditional literature reviews and require a multi-person research team. See this PredicTER tool to get a sense of a systematic review timeline. Other types of evidence synthesis may take less or more time, depending on the scope.
Not sure what type of review will help you meet your research goals? Here is an overview of some common types of reviews:
| Type of Review | Common Characteristics |
|---|---|
| Literature review | Generic term; may or may not be systematic. The author has a lot of leeway to decide on the review's scope, comprehensiveness, format, etc. Typically not considered evidence synthesis; instead, literature reviews often provide a narrative overview of select, relevant literature on a topic; hence they are also sometimes called narrative reviews. Brief literature reviews are often part of a larger academic paper. |
| Systematic review | Researchers conduct a systematic search for research evidence on a well-defined topic, usually following relevant guidelines and established procedures that help ensure comprehensiveness and reduce bias. The researchers compare, evaluate, and synthesize evidence. This process is usually time-intensive, taking a few months to a year or more to complete, and done by a team of at least 3 researchers. Very common in the health sciences, and becoming more common over the past decade in the social sciences. |
| Scoping review or evidence map | Researchers conduct a systematic search for research evidence on a well-defined topic, usually following relevant guidelines and established procedures that help ensure comprehensiveness and reduce bias. Though they may evaluate existing evidence, researchers seek to identify research gaps and opportunities for evidence synthesis, rather than attempting to synthesize the evidence. This process is usually time-intensive, taking a few months to a year or more to complete, and done by a team of at least 3 researchers. |
| Rapid review | Researchers apply the same methodology as a systematic review but in a limited timeframe made possible by methodological shortcuts (e.g., limiting search terms). These shortcuts are stated and justified in the final manuscript. Useful for addressing issues needing quick decisions, but an elevated risk of bias is often the trade-off for the compressed schedule. |
| Mixed-methods review | Researchers systematically synthesize a combination of qualitative and quantitative data, either separately for a variety of sub-questions or together for a single research question. This approach can be challenging due to the variability of the available data. |
| Umbrella review | Researchers review and analyze other systematic reviews on a topic. The topic is often more broad than in a typical systematic review, e.g., a comparison of competing interventions. |
| Meta-analysis | May be conducted independently of or as part of a systematic review. Researchers use statistical techniques to combine findings from various quantitative studies, then objectively evaluate, synthesize, and summarize results. |