There is a parallel activity which includes applied research, exploratory development, and engineering development. Far more is known about the flow of information among scientists than among technologists. From the knowledge that is available, however, the communication patterns in the 2 areas of activity are not only largely independent of one another, but qualitatively different in their nature. This difference is reflected most clearly in the mechanisms by which information is diffused within the 2 sets of practitioners. These differences and the nature of the communication process between science and technology are discussed.