The present article considers a fundamental question in evaluation research: "By how much do program effects vary across sites?" The article first presents a theoretical model of cross-site impact variation and a related estimation model with a random treatment coefficient and fixed site-specific intercepts. This approach eliminates…

Background: Evaluations of substance use screening and brief intervention (SBI) curricula typically focus on learner attitudes and knowledge, although effects on clinical skills are of greater interest and utility. Moreover, these curricula often require large amounts of training time and teaching resources. This study examined whether a 3-hour…

In this article we report findings from research through the Center for Research on the Educational Achievement and Teaching of English Language Learners (CREATE), a National Research and Development Center. In our study we examined the efficacy of a model of instruction for English learners, the Sheltered Instruction Observation Protocol (SIOP)…