This report has described the sample of children, classrooms, and programs included in our analyses of the relationships between classroom instruction and child-level outcomes for preschool-aged DLLs. It also described those child-level outcomes—including children’s language, literacy, math, executive functioning, and social-emotional skills—and how child, family, classroom, and program characteristics were related to them. This information serves as important context for the instructional analyses that are discussed in the series of research briefs associated with this report. (author abstract)