When evaluators plan site-randomized experiments, they must conduct the appropriate statistical power analyses. These analyses are most likely to be valid when they are based on data from the jurisdictions in which the studies are to be conducted. In this method note, we provide software code, in the form of a SAS macro, for producing statistical…

In this experimental study, 151 middle school students explored 3 historical controversies, first reading and discussing primary source documents in groups, then writing arguments on their own. Students were either randomly assigned to an experimental condition, using argumentative schemes and critical questions as guides during discussions, or to…

Education policymakers have shown increased interest in incentive programs for teachers based on the outcomes of their students. This article examines a program in which bonuses were awarded to teams of middle school teachers based on their collective contribution to student test score gains. The study employs a randomized controlled trial to…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

The effects of relaxation exercises on orthography performance in language arts education of fifth to seventh graders were experimentally tested. Participants were 399 basic secondary school students and their language arts teachers from the Hauptschule, a German type of secondary education covering grades five to nine that leads to a basic…