Researchers, policymakers, and practitioners are often interested in a number of demographic characteristics of students, such as race and ethnicity, language background, immigration status, and poverty. For example, the federal No Child Left Behind (NCLB) legislation requires schools and districts to report student test scores separately for major racial and ethnic groups, English learners, disabled students, and poor students. Yet while demographic populations are often viewed as distinct, in fact, these populations frequently intersect.