A comprehensive theory of instruction is needed that (1) acknowledges the centrality of communication to instruction; (2) recognizes that instruction involves changes in student knowledge, affect, and behavior; and (3) reflects a systematic orientation to instruction. The literature in diffusion, particularly in the area of the communication of innovation, provides a logical step toward meeting this need. The innovation-decision process, change agent characteristics, and attributes of the innovation are three elements affecting the successful communication of an innovation. Each of these elements has implications for instruction. The learning process is a function of stages of the innovation-decision process; teachers are change agents. Further, it is reasonable to suggest that five primary attributes of the diffusion process (complexity, compatibility, observability, relative advantage, and "trialability") are likely to be related to student learning. In fact, preliminary results of a study investigating elements of the diffusion process in an instructional context suggest that the classroom teacher should develop curricula that have specific attributes; curricula should be relatively easy for the student to experiment with, appear to offer an advantage over the student's current knowledge and behavior, have a clearly visible impact on the student, and be relatively easy to understand. (Suggestions are offered for using the communication model in instructional research and applied contexts.) (RH)