Traditionally, cluster randomized controlled trials are analyzed with the average intervention effect of interest. However, in populations that contain higher degrees of heterogeneity or variation may differ across different values of a covariate, which may not be optimal. Within education and social science contexts, exploring the variation in…

A common theme uniting articles in this special issue is a focus on aptitude-by-treatment interactions (ATIs). This timely and welcome focus allows the field to synthesize current substantive findings on ATIs in educational intervention research in both reading and math domains. In this methodological commentary, we begin by reviewing traditional…

Lord's Paradox occurs when a continuous covariate is statistically controlled for and the relationship between a continuous outcome and group status indicator changes in both magnitude and direction. This phenomenon poses a challenge to the notion of evidence-based policy, where data are supposed to be self-evident. We examined 50 effect size…

In contrast to Early Intensive Behavioral Intervention (EIBI), there are far fewer meta-analyses evaluating Naturalistic Developmental Behavioral Interventions (NDBIs) (Schreibman et al., 2015). Indeed, Pivotal Response Treatment (PRT)--a prominent NDBI--lacks meta-analytic studies. In the context of developing a line of research on the…

Design-based methods have recently been developed as a way to analyze data from impact evaluations of interventions, programs, and policies. The impact estimators are derived using the building blocks of experimental designs with minimal assumptions, and have good statistical properties. The methods apply to randomized controlled trials (RCTs) and…

A new design-based theory has recently been developed to estimate impacts for randomized controlled trials (RCTs) and basic quasi-experimental designs (QEDs) for a wide range of designs used in social policy research (Imbens & Rubin, 2015; Schochet, 2016). These methods use the potential outcomes framework and known features of study designs…

Design-based methods have recently been developed as a way to analyze data from impact evaluations of interventions, programs, and policies (Imbens and Rubin, 2015; Schochet, 2015, 2016). The estimators are derived using the building blocks of experimental designs with minimal assumptions, and are unbiased and normally distributed in large samples…

Two previous studies examining 5 empirical educational psychology research journals (Hsieh et al., 2005; Robinson, Levin, Thomas, Pituch, & Vaughn, 2007) found that in the 21-year period from 1983 to 2004, there was a decrease in intervention and randomized experimental research, whereas in the 10-year period from 1994 to 2004, there was an…

This meta-analysis used hierarchical linear modeling to examine 115 single-case studies with 343 participants that examined the effectiveness of social skills interventions for individuals with autism spectrum disorder (ASD). The average effect size of the included studies was 1.40 (SD = 0.43, 95% CL = 1.32-1.48, N = 115). In the further, several…

This summary reports the findings from two cluster-randomised trials of Drinkaware's school-based In:tuition life skills and alcohol education intervention: one trial of the programme for 10-11 year olds in primary schools, and another for 12-13 year olds in secondary schools. The trials have been carried out by the National Foundation for…