The extent to which education interventions have been studied and the range of effects typically observed.

!e EEF’s education database is comprised of thousands of education research studies from across the globe, all focused on measuring the impact of education interventions on students’ outcomes. !e studies in the database have been coded to enable analysis and searching across a range of factors, including country, pupil age and type of intervention. Rather than simply focusing on the impact of interventions, the database also records information about the delivery of interventions (such as the frequency and intensity of the intervention) and detailed quantitative impact data, such as variations in e#ects based on subject or delivery mechanism (such as whether an intervention is delivered by a quali"ed teacher or a classroom assistant). Impact is translated from standardised e#ect sizes to ‘months of learning’ for ease of communication and to aid discussion around the impact of interventions. Months of learning, communicated as a headline "gure for each approach, however, can hide important variation caused by duration of intervention, group size and the test measures used. Building the database containing all of this data allows researchers to examine which factors are driving the impact behind the overall average to "nd the signal amongst the noise. It is this detailed data which makes this education database unique. It will signi"cantly reduce the time and e#ort needed to review the impact of di#erent types of interventions, and to analyse the factors that increase or reduce e#ectivenes