The purpose of this paper is to showcase new research that seeks to provide guidance on the heterogeneity of treatment effects by utilizing the variance of demographic differences in state assessments. This study is focused on a simple randomized block design where students are nested within schools, and within each school students are randomized…

This article provides practical guidance for researchers who are designing studies that randomize groups to measure the impacts of educational interventions. The article (a) provides new empirical information about the values of parameters that influence the precision of impact estimates (intraclass correlations and R[superscript 2] values) and…

Social promotion has long been the normal practice in American schools. Critics of this practice, whereby students are promoted to the next grade regardless of academic preparation, have suggested that students would benefit academically if they were made to repeat a grade. Supporters of social promotion claim that retaining students disrupts them…