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…

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…

In research textbooks, and much of the research practice, they describe, qualitative processes and interpretivist epistemologies tend to dominate visual methodology. This article challenges the assumptions behind this dominance. Using exemplification from three existing visual data sets produced through one large education research project, this…