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.…

I. Purpose of the Study: Detecting whether interventions work or not (through main effect analysis) can provide empirical evidence regarding the causal linkage between malleable factors (e.g., interventions) and learner outcomes. In complement, moderation analyses help delineate for whom and under what conditions intervention effects are most…

This study examined bias reduction in the eight nonequivalent comparison group designs (NECGDs) that result from combining (a) choice of a local versus non-local comparison group, and analytic use or not of (b) a pretest measure of the study outcome and (c) a rich set of other covariates. Bias was estimated as the difference in causal estimate…

Multi-site randomized controlled trials (RCTs) provide unbiased estimates of the average impact in the study sample. However, their ability to accurately predict the impact for individual sites outside the study sample, to inform local policy decisions, is largely unknown. To extend prior research on this question, we analyzed six multi-site RCTs…

Background: In children with a cleft palate with or without a cleft lip (CP±L), some evidence exists for superior results of high-intensity speech intervention (HISI) compared with low-intensity speech intervention (LISI) on speech and health-related quality of life (HRQoL). However, the existing research often involves small sample sizes.…

The purpose of this article is to examine the application of randomized controlled trial (RCT) methodology for determining the efficacy of school-based interventions in general and special education. In education science, RCTs are widely acknowledged as the gold standard of efficacy research, with other methodologies relegated to a lower level of…

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…

The What Works Clearinghouse (WWC) identifies existing research on educational interventions, assesses the quality of the research, and summarizes and disseminates the evidence from studies that meet WWC standards. The WWC aims to provide enough information so educators can use the research to make informed decisions in their settings. This…

The current situation due to the COVID-19 pandemic has had huge consequences in all aspects of our lives, including the development of research activities. Studies involving face-to-face interaction with people, such as randomized controlled trials, were the first affected. The objective of this article is to present the insights on challenges…

Background: Continued professional development (CPD) is required for updated skills and knowledge. This study evaluates the efficacy of a CPD programme for mainstream school teachers. Aims: In an 11-week intervention programme, speech-language therapists (SLTs) presented the participating teachers with whole-class teaching techniques aimed at…

In paired experiments, participants are grouped into pairs with similar characteristics, and one observation from each pair is randomly assigned to treatment. The resulting treatment and control groups should be well-balanced; however, there may still be small chance imbalances. Building on work for completely randomized experiments, we propose a…

This study is a randomized controlled trial of a 12-week community-based group parenting intervention ("CASITA") in Lima, Peru. CASITA improved neurodevelopment in a pilot study of 60 Peruvian children and subsequently scaled to 3,000 households throughout the district. The objective of this study was to assess intervention effectiveness…

ChildFund International (ChildFund) is a child-focused International Non-Governmental Organization (INGO) which, since 1938, has worked with local implementing partners (LIPs), government, and other partner organizations to help create the safe environments children need to thrive. The purpose of this commentary is to reflect on the utility and…

Technology-assisted parent-mediated interventions improve accessibility and are acceptable but not proven to be effective. We conducted a systematic search of 6 databases. We included and analysed results from studies on social and communication outcomes. Sixteen Randomised-Controlled-Trials (RCTs) with 748 participants were included. Most studies…

A substantial number of randomized trials of educational interventions that have been conducted over the past two decades have produced null results, with either no impact or an unreliable estimate of impact on student achievement or other outcomes of interest. The investment of time and money spent implementing such trials warrants more useful…