Sample size determination in multilevel randomized trials (MRTs) and multilevel regression discontinuity designs (MRDDs) can be complicated due to multilevel structure, monetary restrictions, differing marginal costs per treatment and control units, and range restrictions in sample size at one or more levels. These issues have sparked a set of…

In a randomized controlled trial (RCT), some subjects assigned to the treatment condition may not fully comply. Often there is interest in the effect of the treatment within the "principal stratum" of subjects who would comply if assigned to treatment. However, it is unknown which control subjects would have complied if treated and which…

Background/Context: Online training has become an increasingly attractive alternative to traditional training (Laurillard 2016; Castaño-Muñoz et al. 2018). The online delivery of training allows overcoming geographical barriers and reaching higher numbers of participants in a flexible way and at reduced cost. Online training also offers higher…

Implementation intentions are self-regulatory strategies that increase the probability that desired goals will be achieved. While their effectiveness in the short term is well established in the literature, the long-term effects are not. The present study, which was conducted in France during the COVID-19 lockdown, aimed to test whether reminders…

When well-implemented, mediation analyses play a critical role in probing theories of action because their results help lay the ground work for the critical development of a treatment and the iterative advancement of theories that are foundational to a discipline. Despite strong interest in designs that incorporate mediation, few studies have…

In multisite trials, learning about treatment effect variation across sites is critical for understanding where and for whom a program works. Unadjusted comparisons, however, capture "compositional" differences in the distributions of unit-level features as well as "contextual" differences in site-level features, including…

Retention of early career teachers is a critical issue in education, with burnout and self-efficacy serving as important precursors to teachers leaving the field. An integration of the PAX Good Behavior Game (GBG; Barrish et al., 1969) and MyTeachingPartner (MTP; Allen et al., 2015) was tested in a randomized controlled trial (RCT) to investigate…

There is a need for robust evidence about which educational interventions work in preschool to foster children's cognitive and socio-emotional learning (SEL) outcomes. Lab-based individually randomized experiments can develop and refine such interventions, and field-based randomized experiments (e.g., cluster randomized trials) evaluate their…

In the complex world of educational policy, causal inferences will be debated. As we review non-experimental designs in educational policy, we focus on how to clarify and focus the terms of debate. We begin by presenting the potential outcomes/counterfactual framework and then describe approximations to the counterfactual generated from the…

Objective: To determine if treatment of co-occurring adult ADHD and Cannabis Use Disorder (CUD) with extended-release mixed amphetamine salts (MAS-ER) would be effective at improving ADHD symptoms and promoting abstinence. Method: A 12-week randomized, double-blind, two-arm pilot feasibility trial of adults with comorbid ADHD and CUD (n = 28)…

Educational researchers advocate the use of an effect size and its confidence interval to assess the effectiveness of interventions instead of relying on a p-value, which has been blamed for lack of reproducibility of research findings and the misuse of statistics. The aim of this study is to provide a framework, which can provide direct evidence…

Purpose: This article gives an overview of the successes and lessons learned to date of the Education Endowment Foundation (EEF), one of the leading organizations of the What Works movement. Design/Approach/Methods: Starting with its history, this article covers salient components of the EEF's unique journey including lessons learned and…

Within a parallel-group randomized control trial, pain training's impact on Respite Workers' (RW) care approaches and training evaluations was explored. RW (n = 158) from 14 organizations received pain or control training following randomization. Researchers were blind until randomization; allocations were not shared explicitly with…

Online citizen science allows us to bridge the gap between researchers and nonresearchers and to improve the scientific literacy of nonresearchers. The aims of the present study were: (1) to determine whether a 5-week randomized control trial conducted by teachers in their classroom could improve 7- to 12-year-old children's inhibitory control…

The purpose of this study was to examine the effectiveness of an online interprofessional education competency (IPEC) online educational module intervention on the level of interprofessional team collaboration (ITC) on three subscales, as measured with the Assessment of Interprofessional Team Collaboration Scale (AITCS-II) in interprofessional…