If our goal in education research is to produce knowledge that is useful and used, we need to design impact evaluations that value understanding variation as much as understanding average impact. The context in which an intervention is implemented and the characteristics of participants are integral components of the intervention, and we need to…

The growing population of English language learners (ELLs) in U.S. schools and the low academic achievement of many of these learners have been the subject of much debate. A significant related issue is determining the sources of ELLs' difficulty, namely, understanding the distinction between learning disabilities (LD) and learning difficulties…

This analysis is about the role of poverty in school reform. Data from a number of sources are used to make five points. First, that poverty in the United States is greater and of longer duration than in other rich nations. Second, that poverty, particularly among urban minorities, is associated with academic performance that is well below…