Introduction: The What Works Clearinghouse (WWC) reviews rigorous research on educational interventions with a goal of identifying "what works" and making that information accessible to educators and policymakers. In rating the quality of causal research, the WWC has historically prioritized internal validity over external validity. One…

A substantial number of randomized trials of educational interventions that have been conducted over the past two decades have produced null results, with either no impact or an unreliable estimate of impact on student achievement or other outcomes of interest. The investment of time and money spent implementing such trials warrants more useful…

Over the past 15 years, we have seen an increase in the use of cluster randomized trials (CRTs) to test the efficacy of educational interventions. These studies are often designed with the goal of determining whether a program works, or answering the what works question. Recently, the goals of these studies expanded to include for whom and under…

This article addresses the gap between what works in research and what works in practice. Currently, research in evidence-based education policy and practice focuses on randomized controlled trials. These can support causal ascriptions ("It worked") but provide little basis for local effectiveness predictions ("It will work…

Background: The use of randomised controlled trials (RCTs) in education has increased significantly over the last 15 years. However, their use has also been subject to sustained and rather trenchant criticism from significant sections of the education research community. Key criticisms have included the claims that: it is not possible to undertake…

Identifying effective literacy interventions for teachers of very young children is important, but it is not easy. In this case study, we share our experiences implementing a quasi-experimental evaluation of an early literacy program. We describe the design and context of the study and discuss three key issues that we encountered with data…

This report examines the range of factors that might influence the decision by social care professionals on the use of boarding schools as an intervention option for Children in Need (CiN) or children on a Child Protection Plan (CPP). Attempts to conduct a randomised controlled trial (RCT) failed to recruit participants. Initially, failure to…

This paper reviews literature on the rationale, challenges, and recommendations for choosing a nonequivalent comparison (NEC) group design when evaluating intervention effects. After reviewing frequently addressed threats to validity, the paper describes recommendations for strengthening the research design and how the recommendations were…

In order to better assist practitioners and better serve persons with autism spectrum disorders (ASD) and their families, it is vital for professionals to systematically evaluate the existing body of literature and synthesize its scientific evidence, so that the efficacy of research can be translated to evidence-based practices (EBPs) (Wheeler,…

Interest in variation in program impacts--How big is it? What might explain it?--has inspired recent work on the analysis of data from multi-site experiments. One critical aspect of this problem involves the use of random or fixed effect estimates to visualize the distribution of impact estimates across a sample of sites. Unfortunately, unless the…

Intervention research is vital for social work, as it aims to develop practice/program approaches and provide evidence to understand which interventions are effective and for whom. Despite growing attention, little social work research exists that evaluates interventions. Among the reasons for the dearth of intervention research within social work…

This "What Works Clearinghouse Procedures and Standards Handbook (Version 3.0)" provides a detailed description of the standards and procedures of the What Works Clearinghouse (WWC). The remaining chapters of this Handbook are organized to take the reader through the basic steps that the WWC uses to develop a review protocol, identify…

This review examines 105 empirical studies that investigate students' views of the nature of science (VNOS), effects of curricular interventions on changing students' VNOS, and relations between VNOS and demographics, majors, and learning of science. The reviewed studies can be categorized into three theoretical frameworks: the unidimension, the…

The What Works Clearinghouse (WWC) provides online reports to the public about the scientific evidence for educational interventions. The quality of these reports is important because they effectively tell the non-scientific community which programmes do and do not work. The aim of this brief review is to assess WWC's report on a clinically…

The present review examines research on the effects of technology use on reading achievement in K-12 classrooms. Unlike previous reviews, this review applies consistent inclusion standards to focus on studies that met high methodological standards. In addition, methodological and substantive features of the studies are investigated to examine the…