Purpose: This study explored the relation between therapy group size and language outcomes for children receiving school-based language therapy through an implementation science lens. Method: Data for the current study were gathered as part of the Speech-Language Therapy Experiences in Public Schools study. Participants included 273…

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…

Identifying an appropriate class size is an important decision public schools face as they weigh balancing their budget with the impact class size may have on student achievement. This study examined perceptions of South Dakota kindergarten through third-grade teachers, elementary principals, and superintendents concerning optimal class size 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…

Prior research has established the potential for achievement gains from attending smaller classes. However, large statewide class-size reduction (CSR) policies have not been found to consistently realize such gains. A leading explanation for the disappointing performance of CSR policies is that schools are forced to hire additional teachers of…

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…

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…

Given that previous findings on the social distribution of the effects of small classes have been mixed and inconclusive, in the present study I attempted to shed light on the mechanism through which small classes affect the achievement of low- and high-achieving students. I used data from a 4-year, large-scale, randomized experiment (project…

Using a pretest-posttest comparison-group design, this 16-week study investigated the effects of 2 instructional approaches on the phonological awareness, alphabetic knowledge, and early reading of kindergarten children. The primary goal was to compare a form of contextualized instruction based on an adapted interactive writing program with a…

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…