IT seems particularly timely to offer a broad discussion of the background and implementation of the Interdisciplinary Materials Sciences Program of the Advanced Research Projects Agency. It is one which is unique in many respects and has attracted considerable interest within the scientific community. It is revolutionary in character, and there have been numerous inquiries concerning the program from the agencies of the government as well as from industry, research institutes, and university personnel engaged in or associated with materials research. Our purpose is to present some of the fundamental aspects of the program and to provide an insight from which the philosophy, objectives, and implementation will become a coherent pattern.