The What Works Clearinghouse (WWC) Standards Briefs explain the rules the WWC uses to evaluate the quality of studies for practitioners, researchers, and policymakers. 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.…

While there has been some increasing interest in external validity, most work to this point has been in assessing the similarity of a randomized trial sample and a population of interest (e.g., Stuart et al., 2010; Tipton, 2011). The goal of this research is to calculate empirical estimates of the external validity bias in educational intervention…

A systematic analysis of the references to "scientifically based research" (SBR) and closely related terms, such as "peer-reviewed research" (PRR), in the Individuals with Disabilities Education Act (IDEA) legislation, regulations, commentary, and case law reveal that SBR and its primary variants apply largely to state support…

This report focuses on the 7.5 million children in the United States with diagnosable mental illnesses, examining developmental, behavioral and emotional disorders in this group. Progress being made toward understanding, preventing, and treating these disorders is documented, future directions for research are put forth, and critical resource…

This volume examines two-generation interventions as models that represent a new approach to assisting families in poverty. Five of the chapters examine current programs--their design, characteristics of participants, implementation issues, and in one case, evaluation outcomes. Other chapters offer a research and policy context for this…

To make Head Start studies more accessible and to inform concerned audiences about major findings in the research, this volume provides a review of 124 Head Start studies published since 1970 and presents an annotated bibliography containing 1,448 entries on Head Start research undertaken since 1965. The literature review summarizes findings…

This conference brought together directors of research grants and research-based contracts funded by the Division of Innovation and Development of the Office of Special Education and Rehabilitation Services (OSERS). The proceedings contain copies of three speeches given at the conference, along with transcripts of the question-and-answer sessions…