There are unique challenges to estimating causal effects of preschool for students with special needs that have not received attention in the literature. We revisit the Head Start Impact Study (HSIS) to illustrate that when and how special needs is defined has implications for the internal validity of and interpretation of special needs subgroup…

In the past few decades, simulation training has been used to help nurses improve their patient-transfer skills. However, the effectiveness of such training remains limited because it lacks effective ways of simulating patients' actions realistically. It is difficult for nurses to use the skills learned from simulation training to transfer an…

The impact of a school-based violence prevention program, Second Step, on peer victimization and aggression, and emotion regulation was evaluated among 457 sixth graders. A cluster-randomized trial was conducted with classrooms randomly assigned to intervention (n = 14) or control (n = 14) conditions. A repeated measures analysis of covariance on…

This article describes the findings from an efficacy trial of a school-based, universal prevention program designed to reduce aggressive behavior of by strengthening emotion regulation and social information-processing (SIP) skills. Three cohorts of third graders (N = 479) participated in this study. The first cohort participated in the Making…

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…

This is a checklist of key items to get right when conducting a randomized controlled trial to evaluate an educational program or practice ("intervention"). It is intended as a practical resource for researchers and sponsors of research, describing items that are often critical to the success of a randomized controlled trial. A significant…