Schools are a critical setting for improving child nutrition and food security and preventing obesity in the United States. The U.S. Department of Agriculture mandates that the Supplemental Nutrition Assistance Program--Education, known as CalFresh Healthy Living (CFHL) in California, implements obesity prevention efforts that utilize…

Little is known empirically about intraclass correlations (ICCs) for multisite cluster randomized trial (MSCRT) designs, particularly in science education. In this study, ICCs suitable for science achievement studies using a three-level (students in schools in districts) MSCRT design that block on district are estimated and examined. Estimates of…