The benefits of understanding variation apply on multiple levels. Local policymakers and practitioners need to know both the average impact of an intervention and its variation across settings to properly assess its likely benefits and risks for their jurisdictions. For social scientists, cross-site impact variation offers opportunities to learn…

What works to help community college students progress academically? This brief synthesizes 20 years of rigorous research by MDRC, presenting new evidence about key attributes of community college interventions that are positively related to larger impacts on students' academic progress. Findings: Findings are based on a synthesis of evidence from…

The present article provides a synthesis of the conceptual and statistical issues involved in using multisite randomized trials to learn about and from a distribution of heterogeneous program impacts across individuals and/or program sites. Learning "about" such a distribution involves estimating its mean value, detecting and quantifying…

Multisite trials, which are being used with increasing frequency in education and evaluation research, provide an exciting opportunity for learning about how the effects of interventions or programs are distributed across sites. In particular, these studies can produce rigorous estimates of a cross-site mean effect of program assignment…

The present paper, which is intended for a diverse audience of evaluation researchers, applied social scientists, and research funders, provides a broad overview of the conceptual and statistical issues involved in using multisite randomized trials to learn "about" and "from" variation in program effects across…

In this article, the author shares his comments on statistical analysis for multisite trials, and focuses on the contribution of Stephen Raudenbush, Sean Reardon, and Takako Nomi to future research. Raudenbush, Reardon, and Nomi provide a major contribution to future research on variation in program impacts by showing how to use multisite trials…

This paper uses data from the Head Start Impact Study (HSIS), a nationally representative multisite randomized trial, to quantify variation in effects of Head Start during 2002-2003 on children's cognitive and socio-emotional outcomes relative to the effects of other local alternatives, including parent care. We find that (1) treatment and control…

Head Start is the largest publicly funded preschool program in the U.S., and one of its primary goals is to improve the school readiness of low-income children. As has been widely reported, the first randomized trial of Head Start in the program's history found some evidence that it is achieving this goal. Receiving one year of Head Start had…

To help states and districts make informed decisions about the professional development (PD) they implement to improve reading instruction, the U.S. Department of Education commissioned the Early Reading PD Interventions Study to examine the impact of two research-based PD interventions for reading instruction: (1) a content-focused teacher…

Participants in Comprehensive Employment and Training Act-sponsored classroom training, on the job-training, and subsidized work experience were compared to a Current Population Survey sample. Female participants in all types of training had increased earnings (primarily due to increased employment), while males did not. (GDC)

Examines how the autoregressive earnings model developed by Ashenfelter to evaluate job-training programs can produce badly biased estimates of the magnitude and temporal pattern of program effects. Finds that the decay in Ashenfelter's estimated training effect for men was produced by a time-varying bias in his model, and presents a new, more…

Can a multicomponent employment initiative that is located in public housing developments help residents work, earn more money, and improve their quality of life? The Jobs-Plus Community Revitalization Initiative for Public Housing Families (Jobs-Plus, for short) sought to achieve these ambitious goals in difficult environments. Operated as a…

This executive summary describes results of the "Reading First Impact Study: Interim Report." The report presents preliminary findings from the Reading First Impact Study, a congressionally mandated evaluation of the federal government initiative to help all children read at or above grade level by the end of third grade. The No Child…

This paper examines how controlling statistically for baseline covariates (especially pretests) improves the precision of studies that randomize schools to measure the impacts of educational interventions on student achievement. Part I of the paper introduces the concepts, issues, and options involved. Parts II and III present empirical findings…

The Accelerated Schools Approach is a whole-school reform being implemented in more than 1,000 U.S. elementary and middle schools. The program is characterized by a school structure that sets high expectations for students and teachers, a governance structure with broad teacher participation, and a "powerful learning" approach to…