The use of systematic reviews in educational research is a growing phenomenon in the UK, but is highly controversial. This article argues that such reviews have a useful place in a research cycle that wishes to inform and be informed by practice and policy. It proposes and discusses a model of educational research, showing how reviews relate to small or large-scale primary studies.

It is only fair to hold someone accountable for outcomes over which they have sufficient control. The evidence-based approach to education (“evidence-based education,” or EBE) promises to give educators sufficient control over their students’ outcomes by providing access to interventions that are effective according to scientific research. I argue that EBE fails to secure sufficient control because the research on which it relies doesn't establish that interventions are generally effective. If they are to be fair, accountability practices must reflect the (...) limited control educators have, even when using evidence-based interventions that have improved outcomes in other settings. I glean relevant insights by considering accountability for medical practitioners within the context of evidence-based medicine (EBM). (shrink)

Randomised controlled trials (RCTs) are often seen as the 'gold standard' of evaluative research. However, whilst randomisation will ensure comparable groups, trials are still vulnerable to a range of biases that can undermine their internal validity. In this paper we describe a number of common threats to the internal validity of RCTs and methods of countering them. We highlight a number of examples from randomised trials in education and health care where problems of execution and analysis of the RCT has (...) undermined their internal validity. However, awareness of these potential biases can lead to careful planning to avoid or reduce their occurrence. If good quality randomised trials are to inform policy and practice in education then rigorous trials need to be designed that are the least susceptible to threats to their validity. (shrink)

Randomized controlled trials in educational research tend to be small. Small trials can have large, chance, imbalances in important covariates. For studies with sample sizes greater than 50, chance imbalances can be corrected using analysis of covariance; for small trials, however, statistical power is maximized if the trial is balanced and analysis of covariance is used in the analysis. The aim of the present study was to discuss methods of improving covariate balance in trial design and to demonstrate the method (...) of minimization. Using an exemplar of a cluster or class‐randomized trial with 29 classes, we employed minimization to achieve covariate balance. Minimization achieved good balance on four prognostic variables. Many trialists in education use restricted forms of allocation, including pairing or stratified randomization. These approaches have disadvantages. Another approach rarely used in educational research is minimization. Minimization uses a simple arithmetic algorithm to produce balanced groups across a number of important covariates and should be more widely used in educational and psychological research. (shrink)