Studied possible effects of small classes on achievement using data from Project STAR, a 4-year, large-scale randomized experiment on the effects of class size. There were unambiguous positive effects of small classes on achievement, but no evidence for differentially larger effects of small classes for lower achieving students. (SLD)

Analyzed data from a five-year followup of students in Tennessee's Student/Teacher Achievement Ratio (STAR) project, a four-year large-scale randomized examination of the effects of class size on academic achievement. Results suggest that class-size benefits persist for at least five years and remain large enough to be important to educational…

Analyzed results from a 4-year large-scale randomized experiment on the effects of class size, project STAR in Tennessee. Analyses suggest class size effects that are large enough to be important for educational policy and that are quite consistent across schools. Small classes appear to benefit all kinds of students. (SLD)

Used data from Tennessee's Project STAR, a longitudinal class size experiment, to study the cumulative effects of reduced class size in the early grades on academic achievement. Results indicated that controlling for achievement in the previous year, small classes in grades 1-3 yielded statistically significant additional positive effects on…

Conducted a 6-year followup of almost 4,000 students in Project STAR in Tennessee, a 4-year, large-scale randomized experiment on the effects of class size. Though follow-up data could not be obtained on more than one-half of the students, class size effects persisted for at least 6 years and remained large enough to be of importance for…

Recent research from randomized experiments on class size points to positive effects of small classes that persist for several years, but the evidence about the social distribution of effects is less clear. Some scholars have contended that the immediate effects of small classes are larger for minorities and for disadvantaged persons (e.g., J. D.…

It is widely accepted that teachers differ in their effectiveness, yet the empirical evidence regarding teacher effectiveness is weak. The existing evidence is mainly drawn from econometric studies that use covariates to attempt to control for selection effects that might bias results. We use data from a four-year experiment in which teachers and…

Investigates differential effects of small classes on academic achievement among disadvantaged elementary students using data from Tennessee's Student Achievement Ratio Project. While positive effects of small classes are evident on both reading and mathematics achievement, there is no evidence of differential effects for low socioeconomic status…