Recently, educational researchers and practitioners have turned to value-added models to evaluate teacher performance. Although value-added estimates depend on the assessment used to measure student achievement, the importance of outcome selection has received scant attention in the literature. Using data from a large, urban school district, I…

In this article we examine student performance on mandated tests in grades 3, 4, and 5 in one state. We focus on this interval, which w e term "the fourth grade window," based on our hypothesis that students in grade four are particularly vulnerable to decrements in achievement. The national focus on the third grade as the critical…