Estimated the impact of class size on instructional practices and the use of time in high school mathematics and science courses using data from the National Education Longitudinal Study. Findings reveal that class size has an impact on the use of class time, both instructional and noninstructional. (SLD)

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…