This article examines the statistical precision of cluster randomized trials (CRTs) funded by the Institute of Education Sciences (IES). Specifically, it compares the total number of clusters randomized and the minimum detectable effect size (MDES) of two sets of studies, those funded in the early years of IES (2002-2004) and those funded in the…

Background: Quasi-randomization might expedite recruitment into trials in emergency care settings but may also introduce selection bias. Methods: We searched the Cochrane Library and other databases for systematic reviews of interventions in emergency medicine or urgent care settings. We assessed selection bias (baseline imbalances) in prognostic…

The primary technique that many researchers use to analyze data from randomized control trials (RCTs)--detecting the average treatment effect (ATE)--imposes assumptions upon the data that often are not correct. Both theory and past research suggest that treatments may have significant impacts on subgroups even when showing no overall effect.…

This study offers an evaluation of a community-based educational intervention to enhance the quality of confiding relationships in the LGBT community. Building off the original Marital First Responder (MFR) curriculum and intervention, the MFR-Q targets these confidants and provides an LGBT culturally-specific intervention with the goal of helping…

Applied researchers are increasingly interested in whether and how treatment effects vary in randomized evaluations, especially variation not explained by observed covariates. We propose a model-free approach for testing for the presence of such unexplained variation. To use this randomization-based approach, we must address the fact that the…

Objective: This study reevaluates the effects of a randomized controlled trial (RCT) of job search interventions on labor force participation. In the trial, various methods of job search interventions were included, of which about half were research-based JOBS (Job Opportunity and Basic Skills) interventions and the other half were practice-based,…

This study examined the process by which a web-based sexual violence (SV) prevention program (i.e., "RealConsent") prevents SV perpetration and increases bystander behaviors. Data from 743 college men who participated in a randomized controlled trial were analyzed. Simple and multiple-mediation models were estimated, using several…

Background: Early intervention for autism spectrum disorder (ASD) tends to focus on enhancing social communication skills. We report data collected via focus group discussions as part of a feasibility and acceptability pilot randomized controlled trial (RCT) about a new parent group intervention to manage restricted and repetitive behaviours (RRB)…

The teaching and learning of programming are often considered a difficult topic for both teachers and students, due to its complexity and abstract nature. The traditional teaching approaches are unable to contribute substantially to the development of the necessary cognitive models by the students, producing high rates of failure and dropout in…

The benefits of mindfulness for a variety of clinical and nonclinical populations are well established and there is growing interest in the potential of mindfulness in higher education. This article reports on the results from a randomized wait-list controlled study of Mindfulness-Based Coping With University Life (MBCUL), an adaption of…

Teacher professional development and in-class mentors were used to support structured inquiry with math manipulatives. Twenty-four primary schools (n = 6,628 students) were randomly assigned to treatment and control groups as an experimental field trial to examine the effectiveness of this instructional approach in a scaled-up application in…

Structural quality in childcare centers is considered a precondition for process quality, which in turn is related to children's outcomes. However, the evidence on relations between structural and process quality is mixed. Moreover, despite strong theoretical claims, empirical evidence supporting the indirect relation of structural features…

Whilst research underlines the importance of early mathematics in kindergarten, practitioners need effective and innovative approaches to pedagogy. Currently, very different approaches are deployed from an instructional, educator-led approach based on training programmes to a play-based approach. This intervention study examines the effects on the…

Science curricula and teaching methods vary greatly, depending in part on which facets of science are emphasized, e.g., core disciplinary ideas or science practices and process skills, and perspectives differ considerably on desirable pedagogies. Given the multi-faceted nature of science and the variety of teaching methods found in practice, it is…

To plan group-randomized trials where treatment conditions are assigned to schools, researchers need design parameters that provide information about between-school differences in outcomes as well as the amount of variance that can be explained by covariates at the student (L1) and school (L2) levels. Most previous research has offered these…