This book is the result of a study conducted with 200 high schools in the South to determine what factors make schools effective in educating students and creating a healthy social environment. The book is particularly concerned with improving desegregated high schools and presents specific recommendations for doing so. Using survey data from school personnel and students as well as achievement test scores, the study examines the effects of : (1) various features of desegregation plans; (2) the racial attitudes and behavior of the schools' teaching staff; (3) special programs designed to improve race relations (such as black studies programs, in-service human relations training, biracial committees); (4) extracurricular activities; and (5) modifications of the structure of the school (including tracking, individualization, and cooperative learning). In general, the book argues for the importance of schools building a "social climate" which is favorable both to learning and adolescent development, including intergroup relations. Discussions of the methodology and technical considerations of the study are included throughout the book. (CG)