Reference Resources iconReview Protocols

What Works Clearinghouse (WWC) reviews in this topic area focus on early childhood education (ECE) interventions designed for use in school- or center-based settings with 3- to 6-year-old children who are not yet in kindergarten and are attending a center-based program. The primary focus for early childhood education interventions is on cognitive, language, and behavioral competencies associated with school readiness (specifically, language, cognitive, and social-emotional development, print knowledge, phonological processing, early reading and writing, and math).

Systematic reviews of evidence in this topic area address the following questions:

  • Which ECE interventions improve preschool children’s school readiness (specifically, their language, cognitive, and social-emotional development, print knowledge, phonological processing, early reading and writing, and math)?
  • Does the effectiveness of ECE interventions differ by type of outcome?
  • Which ECE interventions are particularly effective for which children?


Table of Contents

  • Overview
  • Eligibility Criteria and Evidence Standards
  • Literature Search Methodology

Protocol Details

  • Version: 3.0
  • Released: January 2014
  • Version: 2.0
  • Released: October 2009
  • Version: 1.0
  • Released: December 2005

What is a Protocol?

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.

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.

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