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…

The search for the best educational environment, especially in terms of class size, is an important educational issue for parents, teachers, administrators, and government officials. Parents and educators argue that smaller class size leads to more effective teaching and improved learning for students. Government officials argue that substantial…