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.…

Using emergent motivation theory, this study analyzes the relationships between high school students' perceptions of their reading skills, task challenge, and personal control over assigned reading activities and their reading engagement (i.e., interest, enjoyment, and concentration) during science instruction. The study also examines how…