In education, multisite trials involve randomization of pupils into intervention and comparison groups within schools. Most analytical models in multisite educational trials ignore that the impact of an intervention may be school dependent. This study investigates the impact of statistical models on the uncertainty associated with an effect size…

It is not uncommon for randomised trials in education to have the performance of sample members in national examinations as their primary outcome. In many cases, examination results are available as summary measures only. Taking the example of GCSE examination results in England, this paper shows that using summary measures of an underlying score…

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…

At every stage since the start of the pandemic, decisions across education and childcare have been informed by the scientific and medical evidence -- both on the risks of coronavirus (COVID-19) infection, transmission and illness, and on the known risks to children and young people not attending education settings -- balancing public health and…

It is generally agreed that learning about the Holocaust has some impact on students. However, discussions about the nature and magnitude of impact tend to be intuition-based rather than evidence-based. This is exacerbated by studies giving insight into how Holocaust education is related to salient variables rather than studies which demonstrate…

This paper describes the context, processes and issues experienced over 5 years in which a RCT was carried out to evaluate a programme for children aged 7-8 who were struggling with their reading. Its specific aim is to illuminate questions about the design of complex teaching approaches and their evaluation using an RCT. This covers the early…

Cluster Randomized Trial (CRT) designs are inherently multilevel and reflect the hierarchical structure of schools and the wider education system. To capture this multilevel nature, CRTs are commonly analysed using multilevel (or hierarchical) linear models. It is fairly common for CRT designs and analyses to include school and individual/pupil…

The significance of a process evaluation for understanding randomised controlled trials (RCTs) of complex teaching interventions in a classroom setting is discussed in relation to the evaluation of the Integrated Group Reading (IGR) programme trial. This process evaluation is based on realist principles and draws on different data sources. The…

The paradigm of evidence-based education continues to inform the development of policy in a number of countries. At its simplest level, evidence-based education incorporates evidence, often that provided by randomised controlled trials, into classroom practice. England's Education Endowment Foundation is in the process of exporting evidence-based…

Since the 1990s, there have been repeated calls for the systematic use of randomised controlled trials (RCTs) to inform educational decision-making. The advent of the Education Endowment Foundation (EEF) -- described as England's What Works Centre for Education -- in 2011 has made this a reality in England: by 2020, over a third of English schools…

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…

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…