Audience Response Systems (ARS) are a technologies that show promise in helping large groups or classrooms be more effective. We explore the phenomenon of large-group process interactivity in interpersonal computer-mediated communication in the specific case of large classrooms. We develop a general theoretical model of interactive media and then extend it to ARS and develop testable hypotheses regarding how interactivity affects, efficiency, communication quality, status effects and both process and outcome satisfaction in large classrooms. We then present the method and results of a theory-driven quasi-experiment comparing a classroom using ARS to a traditional classroom across two academic quarters. The results reveal that ARS when applied to a large classroom has several advantages over a traditional lecture format of instruction.