This paper presents a model of an interactive mode for instructional research and development that might yield both curriculum products and scientific knowledge concerning learning and instruction. Curriculum development is discussed as an applied science and as an art, using specific research and development efforts conducted at the Learning Research and Development Center to highlight the present and potential character of the interactive model. Consideration is given to the roles of task analysis, diagnosis of learner characteristics, design of curricula and learning environments, and assessment and evaluation in the development of instructional programs. (Author)