Every aspect of children's lives affects their ability to learn and succeed in school. However, conditions associated with poverty environments are major factors in students' dropping out. Children whose home environments and social backgrounds result in development different from the mainstream enter school at a distinct educational disadvantage. This publication is the result of a comprehensive review of the literature on research and best practice. It provides and in-depth look at: factors that place students at risk; the core organizational, instructional, and curricular structures of schools; and the strategies that have proven effective with students in at-risk situations. Strategies include those for prevention--actions taken to anticipate, forestall, or deal with problems before they irreparably impair a student's ability to perform successfully in school; mediation-- the process of providing an educational environment that ensures success for all students; and intervention--actions designed to interrupt or modify problems that are negatively affecting students' performances. It argues that restructuring the educational system is an essential prerequisite to successful and lasting educational reform. Chapters are: (1) The Need for Systemic Change; (2) Restructuring the System; (3) Prevention Strategies; (4) Mediation Strategies; (5) Intervention Strategies; and (6) Summary. Contains 184 references. (JBJ)