The authors evaluate the success of Arizona's program for English Learners (ELs) twelve years after the implementation of Proposition 203 to determine whether it meets the "third prong" test of Castañeda v. Pickard (1981), which requires a demonstration of the effectiveness of a program after its implementation. This study is a follow-up…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

This study explored the relationships among the components of the Arizona Department of Education's new teacher evaluation model, with a particular focus on the extent to which ratings from the state model's teacher observation instrument differentiated higher and lower performance. The study used teacher-level evaluation data collected by the…