This 2-year longitudinal study is being conducted better to understand the lives of secondary school students as they move from one social setting to another and to draw implications for learning as teachers are provided with a more holistic picture. The study describes students' interrelationships with family, school, and peers; perceptions of boundaries between worlds; and adaptation strategies employed in order to move from one context to another. Participants include 54 diverse students attending 4 large, urban, desegregated high schools. Data were gathered from student interviews, classroom observation, school records, demographic and descriptive material, and teacher interviews. A model has emerged identifying four types of students. The first type comes from a two-parent household valuing family cohesiveness and functioning in a world that is congruent and offers smooth transitions. The second belongs to a world that is different with respect to culture, ethnicity, socio-economic status, or religion, but within which the youngster manages successfully to traverse boundaries. The third type represents students whose worlds are different and who cross boundaries only under certain conditions. The fourth type includes those who describe boundary crossing as impenetrable and insurmountable. Possibly the most significant implication of the multiple worlds model is that it provides teachers and others a way of thinking about students in a more holistic way. (LL)