Education decisionmakers need access to the best evidence about the effectiveness of education interventions, including practices, products, programs, and policies. It can be difficult, time consuming, and costly to access and draw conclusions from relevant studies about the effectiveness of interventions. The What Works Clearinghouse (WWC)…

An aspect of a study is considered a confounding factor if it is not possible to tell whether the difference in outcomes is due to the intervention, the confounding factor, or both. In What Works Clearinghouse (WWC) study reviews, certified reviewers look for a specific type of confounding factor: those that occur when a component of the study…

The What Works Clearinghouse (WWC) examines manuscripts (that is, journal articles, working papers, dissertations, or other publications or pieces of written research presented as complete sets of findings) to determine if they are eligible to be included in a specific review effort. The WWC first determines whether the manuscript contains a…

Many studies of education interventions make claims about impacts on students' outcomes. Some studies have designs that enable readers to make causal inferences about the effects of an intervention but others have designs that do not permit these types of conclusions. To help policymakers, practitioners, and others make sense of study results, the…

Underlying all What Works Clearinghouse (WWC) products are WWC Study Review Guides, which are intended for use by WWC certified reviewers to assess studies against the WWC evidence standards. As part of an ongoing effort to increase transparency, promote collaboration, and encourage widespread use of the WWC standards, the Institute of Education…

This document provides step-by-step instructions on how to complete the Study Review Guide (SRG, Version S3, V2) for single-case designs (SCDs). Reviewers will complete an SRG for every What Works Clearinghouse (WWC) review. A completed SRG should be a reviewer's independent assessment of the study, relative to the criteria specified in the review…

For the 2013 study, "Evaluation of the i3 Scale-up of Reading Recovery Year One Report, 2011-12," researchers examined the Year 1 impacts of the Investing in Innovation (i3) scale-up of "Reading Recovery"®, a short-term intervention for struggling readers, on the reading achievement of first-grade students. The analytic sample…

For the 2014 study, "A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children", researchers examined the effect of a daily before-school physical activity program on behavioral outcomes of students in grades K-2. The study sample included 202 students who…

This What Works Clearinghouse (WWC) topic report addresses reading interventions for students in grades K-3, including core reading curricula, programs, or products to be used as supplements to other reading instruction, programs that focus on staff development, and literacy software. The WWC review on beginning reading focuses on programs…