This study addresses several methodological problems that have confronted prior research on the effect of class size on student achievement. Unlike previous studies, this analysis accounts for the hierarchical data structure of student achievement, where grades are nested within classes and students, and considers a wide range of class sizes…

This paper introduces an empirical strategy to estimate dynamic treatment effects in randomized trials that provide treatment in multiple stages and in which various noncompliance problems arise such as attrition and selective transitions between treatment and control groups. Our approach is applied to the highly influential four year randomized…

Finding an unequivocable answer to the class size issue is vitally important to the future of American public education. Sorting out conflicting viewpoints and determining supportable conclusions are this report's primary purpose. Three factors--research motivation, the effects of confounding variables, and problems related to distinguishing…