The author begins with a discussion of definitions of mental retardation, early developments in the care of the mentally retarded, trends in the institutional population, and the disillusionment and dissatisfaction being expressed by professionals, consumer groups, and interested citizens. The detrimental effects of institutionalization documented in research are noted. After listing the obstacles to change, the author presents the principal tenets of the new ideology on care of the mentally retarded: retarded persons should be viewed developmentally, capable of growth and learning, regardless of level of retardation or age; retarded persons should live like nonretarded persons to the greatest degree possible; consumers and their representatives should be maximally involved in planning, programming, and decision-making; legal and human rights of retarded persons must be recognized and protected; national standards should be developed to ensure quality of residential services for the mentally retarded; expanding technology should continue to improve residential services and to decrease the need for institutionalization; and wherever possible, retarded persons should be integrated into society and participate as fully as possible in the activities of the culture to which they belong. Eighteen conclusions describe the probable developments in the next ten to twenty years. (Author/IRT)