This paper introduces a simple, quotient effect size, termed (for 'quotient'), suitable for reporting on the effectiveness of educational interventions. The quotient effect size for a pre-test-post-test design is defined as the gain score (i.e. post-test minus pre-test) for the intervention group, divided by the gain score for the control group.…

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…

Over the last twenty years, education researchers have increasingly conducted randomised experiments with the goal of informing the decisions of educators and policymakers. Such experiments have generally employed broad, consequential, standardised outcome measures in the hope that this would allow decisionmakers to compare effectiveness of…

Over the past 15 years, we have seen an increase in the use of cluster randomized trials (CRTs) to test the efficacy of educational interventions. These studies are often designed with the goal of determining whether a program works, or answering the what works question. Recently, the goals of these studies expanded to include for whom and under…

Early intervention efforts have been effective in reducing disruptive behaviors and the probability of poor developmental outcomes. Early interventions include common practice elements to improve social functioning and decrease problem behaviors that disrupt the teaching-learning process. The First Step Next intervention has been well validated…

More aggregate data on school performance is available than ever before, opening up new possibilities for applied researchers interested in assessing the effectiveness of school-level interventions quickly and at a relatively low cost by implementing comparative interrupted times series (CITS) designs. We examine the extent to which effect…

Using an RD design provides statistically robust estimates while allowing researchers a different causal estimation tool to be used in educational environments where an RCT may not be feasible. Results from External Evaluation of the i3 Scale-Up of Reading Recovery show that impact estimates were remarkably similar between a randomized control…

Educational stakeholders are keen to know the magnitude and importance of different interventions. However, the way evidence is communicated to support understanding of the effectiveness of an intervention is controversial. Typically studies in education have used the standardised mean difference as a measure of the impact of interventions. This…

Purpose: This report investigates whether parent-reported stuttering severity ratings (SRs) provide similar estimates of effect size as percentage of syllables stuttered (%SS) for randomized trials of early stuttering treatment with preschool children. Method: Data sets from 3 randomized controlled trials of an early stuttering intervention were…

The objective of this meta-analysis is to rigorously assess the participant effects of private school vouchers, or in other words, to estimate the average academic impacts that the offer (or use) of a voucher has on a student. This review adds to the literature by being the first to systematically review all Randomized Control Trials (RCTs) in an…

Executive functions (EFs) develop rapidly in preschoolers and lay an important foundation for school readiness. One potential method of supporting EF development is through mindfulness-based interventions (MBIs). Whereas studies with older children and adults have supported this approach, research with young children has been more limited. In the…

Cluster randomized experiments are now widely used to examine intervention effects in prevention science. It is meaningful to use empirical benchmarks for interpreting effect size in prevention science. The effect size (i.e., the standardized mean difference, calculated by the difference of the means between the treatment and control groups,…

Background: Children with intellectual and developmental disabilities (IDD) experience heightened attention difficulties which have been linked to poorer cognitive, academic and social outcomes. Although, increasing research has focused on the potential of computerised cognitive training in reducing attention problems, limited studies have…

Purpose: The aim was to evaluate the effectiveness of computer-assisted input-based intervention for children with speech sound disorders (SSD). Method: The Sound Start Study was a cluster-randomized controlled trial. Seventy-nine early childhood centers were invited to participate, 45 were recruited, and 1,205 parents and educators of 4- and…

Research Findings: In Study 1, we observed 32 Chinese kindergarteners playing a number board game with their caregivers in dyads. Number board game playing provided important opportunities for kindergarteners and their caregivers to talk about an array of number concepts, but their numeracy-related exchanges rarely went beyond counting. In Study…