Randomized experiments are a strong design for establishing impact evidence because the random assignment mechanism theoretically allows confidence in attributing group differences to the intervention. Growth of randomized experiments within educational studies has been widely documented. However, randomized experiments within education have…

Background: The Education Endowment Foundation (EEF) is an independent charity that was established in 2011 with the explicit aim of breaking the link between family income and educational achievement in England. Over the seven years since its inception, EEF has contributed to the existing evidence base by funding over one hundred randomised…

In experimental studies, researchers are often interested in secondary research questions that explore important aspects of main findings, such as whether or not program effects vary according to the level of fidelity in which the program has been implemented; or according to the dosage received by individuals participated in the program. In this…