Reference Resource Handbooks & Reviewer Resources

The purpose of the What Works Clearinghouse is to review and summarize the quality of existing research in educational programs, products, practices, and policies. The WWC refines its procedures and standards based on improvements in education research and research synthesis methods. The current version of the Handbook, What Works Clearinghouse Procedures and Standards Handbook, Version 5.0, contains the most up-to-date procedures and standards that WWC uses to review studies, and synthesize and characterize findings.

Current Standards Version 5.0, August 2022 (Revised December 2022)

WWC Version 5.0 Procedures and Standards Handbook (6.9 MB)

Summary of Changes (232 KB) to WWC Procedures and to WWC Version 5.0 Procedures and Standards Handbook

Responses to comments from the public on Draft Version 5.0 Procedures and Standards Handbook (61 KB)

All previous versions of the WWC Procedures and Standards Handbook are available for download.

Prior Standards


Starting in January 2021, the What Works Clearinghouse (WWC) uses the Study Review Protocol in combination with the Procedures and Standards Handbook to guide reviews of all studies. In particular, the Study Review Protocol provides additional information on eligible outcome domains for all topic areas reviewed by the WWC and provides examples of outcome measures that fall within each domain.

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When conducting systematic reviews, the WWC uses the Study Review Protocol to review studies and an accompanying topic area synthesis protocol to define the parameters of the systematic review. The synthesis protocol provides criteria for the literature search; guidance on how to identify and prioritize relevant studies for review and inclusion in evidence synthesis products; and guidance on intervention, sample, and outcome eligibility criteria for the synthesis.

Prior to 2021, studies were typically reviewed using a topic-specific synthesis protocol and the corresponding version of the Procedures and Standards Handbook. In addition to defining the parameters for the review, these protocols described any topic-specific applications of the design standards, such as how to establish baseline equivalence between samples when required.

Use the filters below to search for specific synthesis protocols.

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The WWC provides additional resources for understanding the WWC standards and procedures. Listed below are documents and webinars to help researchers, policymakers, and practitioners learn more about the standards and procedures the WWC uses in its work.

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