Most randomized field experiments experience some attrition. Moreover, the extent of attrition may differ by treatment condition in systematic, non-random ways, biasing estimates of treatment effects and contributing to invalid inferences. We address concerns about non-random attrition by quantifying the conditions necessary in the attritted data…

Multisite trials that randomize individuals (e.g., students) within sites (e.g., schools) or clusters (e.g., teachers/classrooms) within sites (e.g., schools) are commonly used for program evaluation because they provide opportunities to learn about treatment effects as well as their heterogeneity across sites and subgroups (defined by moderating…

In cluster randomized evaluations, a treatment or intervention is randomly assigned to a set of clusters each with constituent individual units of observations (e.g., student units that attend schools, which are assigned to treatment). One consideration of these designs is how many units are needed per cluster to achieve adequate statistical…

As reporting of effect sizes in evaluation studies has proliferated, researchers and consumers of research need tools for interpreting or benchmarking the magnitude of those effect sizes that are relevant to the intervention, target population, and outcome measure being considered. Similarly, researchers planning education studies with social and…

Power in multilevel models remains an area of interest to both methodologists and substantive researchers. In two-level designs, the total sample is a function of both the number of level-2 (e.g., schools) clusters and the average number of level-1 (e.g., classrooms) units per cluster. Traditional multilevel power calculations rely on either the…

Motivational interviewing (MI) is applied in a variety of clinical and coaching models to promote behavior change, with increasing interest in its potential to optimize school-based implementation fidelity. Yet there has been less consideration of fidelity indicators for MI-embedded coaching and links to outcomes. We leveraged secondary data from…

We present an aggregation scheme that increases power in randomized controlled trials and quasi-experiments when the intervention possesses a robust and well-articulated theory of change. Intervention studies using longitudinal data often include multiple observations on individuals, some of which may be more likely to manifest a treatment effect…

This article assesses the likely generalizability of educational treatment-effect estimates from regression discontinuity designs (RDDs) when treatment assignment is based on academic pretest scores. Our assessment uses data on outcome and pretest measures from six educational experiments, ranging from preschool through high school, to estimate…

Background: There is an increased focus on randomized trials for proximal behavioral outcomes in early childhood research. However, planning sample sizes for such designs requires extant information on the size of effect, variance decomposition, and effectiveness of covariates. Objectives: The purpose of this article is to employ a recent large…

The purpose of this study was to evaluate whether the Targeted Reading Intervention (TRI), a professional development and early reading intervention program delivered via webcam technology, could support the early reading progress of English learners (ELs). Participants for the current study were drawn from a larger three-year randomized…

This study evaluated the efficacy of the Preschool First Step (PFS) to Success early intervention for children at risk for attention deficit hyperactivity disorder (ADHD). PFS is a targeted intervention for children 3-5 years old with externalizing behavior problems and addresses secondary prevention goals and objectives. As part of a larger…

A classroom randomized trial (n = 31 classrooms) was conducted using the Second Step Early Learning (SSEL) curriculum compared to usual curricula. Head Start and community preschool classrooms enrolling low income children were randomly assigned to deliver SSEL (n = 16) or usual curricula (n = 15). Data are reported for four year olds…

This study used a randomized controlled trial design to investigate the ROOTS curriculum, a 50-lesson kindergarten mathematics intervention. Ten ROOTS-eligible students per classroom (n = 60) were randomly assigned to one of three conditions: a ROOTS five-student group, a ROOTS two-student group, and a no-treatment control group. Two primary…

This early efficacy study examined the effects of an automated storybook intervention designed to promote school readiness among at-risk prekindergarten children. Story Friends is a small-group intervention in which vocabulary and question-answering lessons are embedded in a series of storybooks.A randomized group design with an embedded…

The field of early intervention is currently faced with the challenge of reducing the prevalence of antisocial behavior in children. Longitudinal outcomes research indicates that increased antisocial behavior and impairments in social competence skills during the preschool years often serve as harbingers of future adjustment problems in a number…