Skip to Main Content

Research Methods--Quantitative, Qualitative, and More: Evidence Synthesis/Systematic Reviews

About Evidence Synthesis and Systematic Reviews

According to the Royal Society, 'evidence synthesis' refers to the process of bringing together information from a range of sources and disciplines to inform debates and decisions on specific issues. They generally include a methodical and comprehensive literature synthesis focused on a well-formulated research question. Their aim is to identify and synthesize all of the scholarly research on a particular topic, including both published and unpublished studies. Evidence syntheses are conducted in an unbiased, reproducible way to provide evidence for practice and policy-making, as well as to identify gaps in the research. Evidence syntheses may also include a meta-analysis, a more quantitative process of synthesizing and visualizing data retrieved from various studies. 

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 (one type of evidence synthesis). Before embarking on an evidence synthesis, it's important to clearly identify your reasons for conducting one. 

(From the Cornell University Library Research Guide, A Guide to Evidence Synthesis)

Open Access Evidence Synthesis Resources

(From the Cornell University Library Research Guide, A Guide to Evidence Synthesis)

New content will be added by the Cornell University team to the list below as it becomes available. Browse our public Zotero library of evidence synthesis research here.  

Training Materials:

The Evidence Synthesis Institute is a training program aimed at library staff supporting evidence syntheses in topics outside of the health sciences, and is fully funded by the Institute of Museum and Library Services (IMLS). The teaching slides from this institute are available here and are licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Slides cover all aspects of the evidence synthesis process and much of the content is applicable to researchers as well as librarians. 

Introduction to Systematic Review and Meta-Analysis: This Massive Open Online Course (MOOC), offered through Coursera, describes and provides instruction for completing all stages of systematic reviews and meta-analyses.

Cochrane Interactive Learning provides tutorials for performing systematic reviews on health-related topics. Module 1: Introduction to Conducting Systematic Reviews is free if you sign up for a Cochrane account. 

INASP provides a free search strategies tutorial to teach users how to clearly define and describe a search topic, identify suitable search terms, pick the best platform(s) on which to search, and use tools and techniques to refine and modify your search. 

Software Tools:

SR Toolbox: a web-based catalogue of tools that support various tasks within the systematic review and wider evidence synthesis process

Rayyan: Free article screening tool 

Zotero: Free citation management tool 

RawGraphs: Free tool for creating appealing graphs

Open Science Framework Preregistration: Free, open source resource for preregistering evidence synthesis protocols, with well-documented guidance on using the tool

SnowGlobe: Free tool for "snowballing" included resources (locating their citations, and those papers that have cited them).  

Grey Literature:

[Grey literature includes reliable sources that may not necessarily have been published in a peer reviewed journal, such as government reports.  PubMed is a good source for grey literature.] PubMed comprises more than 32 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full text content from PubMed Central and publisher web sites. The PubMed Trainer's Toolkit contains instruction materials and short tutorials for navigating PubMed.

Is a Systematic Review for Me?

(From the University of California, San Francisco Library Research Guide, Systematic Reviews)

Systematic review - A systematic review synthesizes data from articles into a summary review which has the potential to make conclusions more certain. Systematic reviews are considered the highest level of evidence in evidence-based medicine (EBM) evidence pyramid. An overview of the systematic review process includes:

  • Time Commitment: Typically 12–24 months from start to finish (may take longer)
  • Team Requirement: Typically 3-5 people at minimum. You will need at least a primary reviewer and a secondary reviewer. Other roles to consider include a subject expert, methodologist/statistician, operations manager, and medical librarian.
  • Topic: A significant question is being asked and answered. The topic is not the subject of a recent review and is not being worked on currently by others.

If this doesn't meet your needs, see "A typology of reviews: an analysis of 14 review types and associated methodologies".

Grant, Maria J., and Andrew Booth. “A Typology of Reviews: An Analysis of 14 Review Types and Associated Methodologies.” Health information and libraries journal 26.2 (2009): 91–108. Web.

For your reference, see these examples of a UCSF-authored systematic review, scoping review, and protocol.

Covidence- A Tool for Systematic Reviews

If you do decide to do a systematic review, UC Berkeley licenses Covidence, a tool to help you. In Covidence, you can import citations, screen titles and abstracts, upload references, screen full text, create forms for critical appraisal, perform risk of bias tables, complete data extraction, and export a PRISMA flowchart summarizing your review process. As an institutional member, our users have priority access to Covidence support.  To access Covidence using the UC Berkeley institutional account, start at this page and follow the instructions.