Controlled choice is a method of desegregation that is voluntary, empowers parents and school staff, and leads to new and exciting school organization and curriculum. To move in the direction of controlled choice, substantial changes in present school organization and operation must be made. This planning guide, based upon the actual experiences of four Massachusetts school systems (Cambridge, Lowell, Worchester, and Fall River), has been prepared to assist local school systems in the exploration, development, and implementation of plans to achieve both desegregation and educational excellence through the introduction of controlled choice. Information is divided into four chapters: "The Case for Choice: Moving Towards Equity and Educational Excellence"; "Choice and Desegregation: Case Examples"; "Planning for Choice: Some Do's and Don'ts"; and "The Development of Choice Plans: An Overview." The introduction of school diversity through the controlled choice system will decentralize the educational decision making process and empower parents, teachers, and administrators to make decisions about the educational philosophy, the curriculum, and the internal organization of their individual school. In cases where desegregation is required, choices must be controlled by admission policies designed to ensure equal and fair integration among all district schools. The bibliography contains 26 references. (KM)