This study examined the effect of class sizes on differences in the trajectories of elementary school students' long-term Japanese language achievement by analyzing panel data composed of standardized achievement test scores at five points from around the end of first grade to around the end of fifth grade. The data for 103 schools, 162 classes,…

Class size reduction policies have been widely implemented around the world in recent years. However, findings about the effects of class size on student achievement have been mixed. This study examines class size effects on fourth-grade mathematics achievement in 14 European countries using data from TIMSS (Trends in International Mathematics and…

Teachers spend most of their time in school in classrooms, and their instruction and teaching practices may be affected by classroom context such as class size. We examine whether teacher effects interact with classroom context such as class size. Specifically, we seek to determine whether teacher effects are more pronounced in small classes than…

Many studies have shown the benefits of smaller class sizes--including random experiments like the Student Teacher Achievement Ratio Project conducted in 79 elementary schools in Tennessee, which assigned children to either small or regular-size classes, as well as large-scale analyses of small and large classrooms that have occurred naturally.…

The findings on the social distribution of the immediate and lasting benefits of small classes have been mixed. We used data from Project STAR and the Lasting Benefits Study to examine the long-term effects of small classes on the achievement gap in mathematics, reading, and science scores (Stanford Achievement Test). The results consistently…

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…