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 paper profiles the student subgroup achievement and gap trends in Wisconsin for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Wisconsin showed across-the-board gains--improvements in reading and math at the basic-and-above, proficient-and-above, and advanced levels for all racial/ethnic…