This report summarizes the complex research literature on quantitative methods for assessing how impacts of educational interventions on instructional practices and student learning differ across students, educators, and schools. It also provides technical guidance about the use and interpretation of these methods. The research topics addressed…

Discusses four ubiquitous major sources of measurement error for individual intelligence scales. Argues that where these sources cannot be directly investigated, they should be estimated rather than ignored. Estimated the typical magnitude of error arising from each of content sampling, time sampling, scoring, and administration. (Author)