This report describes how a longitudinal study was conducted, which examined 1,235 at-risk sixth-grade students (95 percent Black and 5 percent Hispanic) in the Chicago (Illinois) Public Schools and their schools and families. The longitudinal study traced the children's patterns of school adjustment since their enrollment in government-funded kindergarten programs in the 1985-86 school year; studied the effects of their school-based intervention experiences; and assessed the effects of family, school, and individual factors on children that are open to educational alteration. Development, distribution, and collection of survey forms; telephone follow-up of mailed surveys; and data preparation and analyses are described. Data collected included: teacher ratings of children's competence and problem behaviors; children's ratings of their attitudes and behavior in and out of school; field observations of classrooms, children, and teachers; telephone interviews with parents; standardized school achievement test scores; and school records concerning grade promotion, special education placement, and mobility. Additional sections describe procedures used for each data collection effort. Appendix A summarizes data collected from 1985 through 1992. Appendix B includes the seven study instruments. Appendix C presents a report on a study completed in 1991-92 using data from the longitudinal study. (JB)