Results from experimental and nonexperimental studies have shown that teachers differ in their effectiveness. In addition, evidence from nonexperimental studies has indicated that teacher effects last for 3 years in elementary grades. This study uses data from Project STAR and its follow-up study, the Lasting Benefits Study, to examine whether…

This article addresses three questions: Does reduced class size cause higher academic achievement in reading, mathematics, listening, and word recognition skills? If it does, how large are these effects? Does the magnitude of such effects vary significantly across schools? The authors analyze data from Tennessee's Student/Teacher Achievement Ratio…

This paper addresses the relationship between class size and student-teacher interactions as an explanation for effects of class size on achievement. Observations were conducted in kindergarten and Grade 1 classes from 46 Dutch primary schools in order to address the effect of class size on the amount and type of student-teacher interactions. The…

In Project STAR, 11,571 students in Tennessee and their teachers were randomly assigned to different classrooms within their schools from kindergarten to third grade. This paper evaluates the long-term impacts of STAR using administrative records. We obtain five results. First, kindergarten test scores are highly correlated with outcomes such as…

The California class size reduction program provided schools with cash rewards for K-3 classes of 20 or fewer students. I show how program rules made it possible for schools to save money by using mixed-grade classes to meet class size reduction obligations while maintaining larger average class sizes. I also show that this smoothing of students…

The study explored the effects of two kindergarten program organization factors--length of school day and class size--on kindergartners' reading, math and general knowledge achievement at the end of the kindergarten year. Two waves of data were drawn from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K) with an…

Although experimental results indicate that smaller classes promote higher achievement in early elementary school, the broader literature on class-size effects is inconclusive. This seeming contradiction raises questions about the generalizability of experimental evidence, an issue that this article addresses by examining the effects of class size…