The changing role of research in curriculum development since the late 1950's is reviewed. Factors are discussed that have affected the prevailing attitudes toward research and its value, including its role in fields other than education and the mixed success with which various research and development models have met in education. Particular emphasis is placed on the widespread acceptance of the research-development-diffusion model and its practical limitations, and on attempts to revise or replace the model with others which take greater cognizance of the practitioner's role in effective curriculum development. The educational research and development activities of the Schools Council of the United Kingdom and other research centers around the world supply examples of shifts and trends in research policies. The study examines the shift in scale of research and of programs based on research findings, the adoption of the team approach to curriculum development, and the ambiguities of the school improvement movement. Conclusions lead to the advocacy of the application of a new research-evaluation-development model, less linear and more open-ended than the earlier model, that maintains the essential value of research. (PGD)