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 book is designed to provide knowledge about educational research and to help graduate students in education organize and conduct their own research. No prior familiarity with the principles, procedures, or terminology of educational research is required. Chapters are: (1) "Educational Research: Its Nature and Rules of Operation"; (2) "Types…