Evidence-based education aims to support policy makers choosing between potential interventions. This rarely involves considering each in isolation; instead, sets of evidence regarding many potential policy interventions are considered. Filtering a set on any quantity measured with error risks the "winner's curse": conditional on…

This paper seeks to raise awareness among educational researchers and practitioners of some significant weaknesses and internal contradictions of randomised control trials (RCTs). Although critiques throughout the years from education scholars have pointed to the detrimental effects of this experimental approach on education practice and values,…

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…

In this commentary, we complement other constructive critiques of educational randomized control trials (RCTs) by calling attention to the commonly ignored role of context in causal mechanisms undergirding educational phenomena. We argue that evidence for the central role of context in causal mechanisms challenges the assumption that RCT findings…

In this commentary, we complement other constructive critiques of educational randomized control trials (RCTs) by calling attention to the commonly ignored role of context in causal mechanisms undergirding educational phenomena. We argue that evidence for the central role of context in causal mechanisms challenges the assumption that RCT findings…

This paper discusses, compares, and contrasts 4 different models for bringing evidence from randomised controlled trials (RCTs) into practice and into practical reasoning. I look at what questions the models can and cannot answer, what role they accord to RCT evidence, and what their possible attraction for practitioners might be. The models are…

This paper examines the insistent claims by advocates of evidence-based teaching that it is a rigorous scientific approach. The paper questions the view that randomised controlled trials and meta-analyses are the only truly scientific methods in educational research. It suggests these claims are often based on a rhetorical appeal which relies on…

EBP -- evidence-based policy and practice -- has generated intense controversy. A rough continuum of positions can be discerned: At one pole are "tough-minded" commentators distinguished by their support of EBP; however, there are serious internal differences in this camp, for some regard randomised field trials (RFTs) as the gold…

Background/Context: When a researcher tests an educational program, product, or policy in a randomized controlled trial (RCT) and detects a significant effect on an outcome, the intervention is usually classified as something that "works." When the expected effects are not found, however, there is seldom an orderly and transparent…

Within evidence-based education, results from randomised controlled trials (RCTs), and meta-analyses of them, are taken as reliable evidence for effectiveness -- they speak to "what works". Extending RCT results requires establishing that study samples and settings are representative of the intended target. Although widely recognised as…

This article addresses the gap between what works in research and what works in practice. Currently, research in evidence-based education policy and practice focuses on randomized controlled trials. These can support causal ascriptions ("It worked") but provide little basis for local effectiveness predictions ("It will work…

Background: The use of randomised controlled trials (RCTs) in education has increased significantly over the last 15 years. However, their use has also been subject to sustained and rather trenchant criticism from significant sections of the education research community. Key criticisms have included the claims that: it is not possible to undertake…

School-based evaluations of interventions are increasingly common in education research. Ideally, the results of these evaluations are used to make evidence-based policy decisions for students. However, it is difficult to make generalizations from these evaluations because the types of schools included in the studies are typically not selected…

As a systemic approach to improving educational practice through research, "What Works" has come under repeated challenge from alternative approaches, most recently that of improvement science. While "What Works" remains a dominant paradigm for centralized knowledge-building efforts, there is need to understand why this…

Background: Most studies of teacher professional development (PD) do not rigorously test impact on teaching practice and student learning. This makes it difficult to define what is truly "effective." The "Science Teachers Learning from Lesson Analysis" (STeLLA) PD program, in contrast, was studied in a cluster randomized…