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…

Alan Krueger's reanalyses of Eric Hanushek's school-productivity data show that Hanushek's "money doesn't matter" conclusions (influential in several states' education-finance hearings) have no factual basis. Hanushek excluded Tennessee's student/teacher ratio study (Project STAR). Also, class size is influencing students' success in…

Conclusive research has shown the benefits of small class size (1:15), especially for primary grades. Large-scale projects in Indiana and Tennessee and numerous smaller studies found that youngsters in small classes obtain higher test scores, participate more eagerly, demonstrate improved behavior, and retain these benefits in later schooling…

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…

Using research to develop a solid educational foundation can accommodate diverse forces confronting educators, initiate systemic change, and help solve the pupil-teacher ratio (PTR)/class-size puzzle. Small K-3 classes are effective and can be efficient if changes are research-based and exploit class-size and PTR differences. (25 references) (MLH)

Reviews Tennessee's Project Student/Teacher Achievement Ratio (STAR) and puts the results in the context of other nonexperimental evidence about class size. Nonexperimental evidence does not support any achievement gains attributable to class-size reduction, and empirical evidence from STAR has design and implementation flaws that cast doubt on…

Reviews research into class size effects from a methodological viewpoint, concentrating on various strengths and weaknesses of randomized controlled trials (RCT) and observational studies. Discusses population definitions, causation, and generally sets out criteria for valid inferences from such studies. Illustrates with new findings from data in…