There is a burgeoning body of evidence on the average impacts of educational programs. Yet, for many local decision makers, because impacts can vary across sites, the question of whether a certain program will work in their particular district or school remains. This article addresses the question of the generalizability of large-scale average…

In an effort to reduce viral transmission, many schools are planning to reduce class size if they have not reduced it already. Yet the effect of class size on transmission is unknown. To determine whether smaller classes reduce school absence, especially when community disease prevalence is high, we merge data from the Project STAR randomized…

Background: Class size reduction (CSR) is an enduring school reform undertaken in an effort to improve academic achievement and has been widely encouraged in the United States. Supporters of CSR often cite the positive contemporaneous and carryover effects of Project STAR. Much has been discussed regarding the robustness of the contemporaneous…

Schools across the United States are facing budgetary pressures on a scale not seen in generations. Times of fiscal exigency force policymakers and education practitioners to pay more attention to the return on various categories of public investment in education. The sizes of the classes in which students are educated are often a focus of these…

The requirements of various educational reform movements such as No Child Left Behind and Race to the Top have left public education systems searching for ways to make sure students are reaching their highest potential. Because of the importance of accountability issues to school systems, it is important to examine ways to help students reach…

Few questions in public education discourse benefit as much from research-based evidence as the question of class size--the pursuit of the ideal number of students that should be co-located for any particular period of instruction. But for policymakers, research on class size can be an embarrassment of riches, and much of the research appears to…

Evidence from Project STAR has suggested a considerable advantage of being in small classes in early grades. However, the extra benefits of additional years in small classes have not been discussed in detail. The present study examined the additional effects of being in small classes for more than 1 year. We find that once previous grade…

This Information Capsule examines the background and history in addition to research findings pertaining to class size reduction (CSR). This Capsule concludes that although educational researchers have not definitively agreed upon the effectiveness of CSR, given its almost universal public appeal, there is little doubt it is here to stay in some…

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…

In recent years, propensity score matching (PSM) has gained attention as a potential method for estimating the impact of public policy programs in the absence of experimental evaluations. In this study, we evaluate the usefulness of PSM for estimating the impact of a program change in an educational context (Tennessee's Student Teacher Achievement…

In this paper, we follow up the important class size reduction randomized experiment in Tennessee in the mid 1980s (Project STAR) to attempt to further understand the long-lasting influences of early education interventions. While STAR led to large test score benefits during the intervention, these benefits quickly faded at its conclusion.…

Although class-size reductions cannot guarantee better student performance, the Tennessee and Wisconsin experiences, along with other studies, suggest that successful programs share key characteristics: concentration in the primary schooling years, classes with not more than 20 students, greater benefits for urban minority students, and alignment…

This paper begins by describing the basic design and scope of Tennessee's Student Teacher Achievement Ratio (Project STAR), which began in 1985. The project was designed to determine the effect of reduced class size on the achievement and development of students in kindergarten through grade three. Findings that demonstrated that students in…

This report presents results from an analysis of the long-term benefits and costs of Success for All (SFA), a school reform program that focuses on promoting early reading success among educationally at-risk students. The program was piloted and implemented in Baltimore elementary schools. This analysis tracks the educational outcomes through…

Since 1984, large-scale, longitudinal, and experimental research on class size has been conducted in Tennessee. Project STAR (Student-Teacher Achievement Ratio) changed in 1989 to the Lasting Benefits Study (LBS) and Project Challenge. In 1985 almost 7,000 students in kindergarten were randomly assigned to either small classes, regular-sized…