Meta-analyses of treatment effects in randomized control trials are often faced with the problem of missing information required to calculate effect sizes and their sampling variances. Particularly, correlations between pre- and posttest scores are frequently not available. As an ad-hoc solution, researchers impute a constant value for the missing…

As reporting of effect sizes in evaluation studies has proliferated, researchers and consumers of research need tools for interpreting or benchmarking the magnitude of those effect sizes that are relevant to the intervention, target population, and outcome measure being considered. Similarly, researchers planning education studies with social and…

When studies use different scales to measure continuous outcomes, standardised mean differences (SMD) are required to meta-analyse the data. However, outcomes are often reported as endpoint or change from baseline scores. Combining corresponding SMDs can be problematic and available guidance advises against this practice. We aimed to examine the…

We conducted a systematic review to identify randomized controlled trials (RCTs) and single case research design (SCRD) studies of children with autism spectrum disorder that evaluate the effectiveness of responsivity intervention techniques for improving prelinguistic and/or language outcomes. Mean effect sizes were moderate and large for RCTs…

This report presents findings from exploratory, descriptive meta-analyses of effect sizes reported by the first 82 EEF evaluations that used a randomised controlled trial (RCT) or clustered RCT impact evaluation design published up to January 2019. The review used a theoretical framework derived from literature with five overarching themes to…

This document summarises key findings from the quantitative strands of a review of the Education Endowment Foundation (EEF) evaluations that had reported from the establishment of EEF in 2011 up to January 2019. The quantitative strands summarised include meta-analyses of effect sizes reported for attainment outcomes and descriptive analyses of…

This document provides supplementary statistical tables to support the review of Education Endowment Foundation (EEF) evaluations. This includes: (1) Descriptive (univariate) tables for all explanatory variables; (2) Tables for the meta-analyses of primary ITT effect sizes; (3) Tables for the meta-analyses of secondary ITT effect sizes; (4) Tables…

Group social skills interventions (GSSIs) are a commonly offered treatment for children with high functioning ASD. We critically evaluated GSSI randomised controlled trials for those aged 6-25 years. Our meta-analysis of outcomes emphasised internal validity, thus was restricted to trials that used the parent-report social responsiveness scale…

Meta-analyses combine the results of multiple studies of a common question. Approaches based on effect size estimates from each study are generally regarded as the most informative. However, these methods can only be used if comparable effect sizes can be computed from each study, and this may not be the case due to variation in how the studies…

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…

Most evaluators have embraced the goal of evidence-based practice (EBP). Yet, many have criticized EBP review systems that prioritize randomized control trials and use various criteria to limit the studies examined. They suggest this could produce policy recommendations based on small, unrepresentative segments of the literature and recommend a…

When cluster randomized experiments are analyzed as if units were independent, test statistics for treatment effects can be anticonservative. Hedges proposed a correction for such tests by scaling them to control their Type I error rate. This article generalizes the Hedges correction from a posttest-only experimental design to more common designs…

Three recent papers have provided sequential methods for meta-analysis of two-treatment randomized clinical trials. This paper provides an alternate approach that has three desirable features. First, when carried out prospectively (i.e., we only have the results up to the time of our current analysis), we do not require knowledge of the…

The aim of the present study is to determine the influence of student-centered methods employed in Turkish language instruction on the academic success of students through meta-analysis. To this end, a literature review was conducted on the relevant studies conducted between 2000 and 2016 in order to determine the studies were suitable for the…

Randomized experiments are commonly used to evaluate the effectiveness of educational interventions. The goal of the present investigation is to develop small-sample corrections for multiple contrast hypothesis tests (i.e., F-tests) such as the omnibus test of meta-regression fit or a test for equality of three or more levels of a categorical…