This paper introduces Button Theory whose two principle goals are, first, to provide a taxonomy of the ways that students might usefully interact with and control a computerbased teacher, and second, to provide a natural mechanism by which they may exercise that control. W e have developed a small but comprehensive set of messages that students would find it useful to convey to a teacher during a tutorial interaction, and have associated each message with a button presented iconically on the computer screen W e describe our experience with the use of Button Theory in a prototype computer-based teaching system, and demonstrate how, even with rather simple mechanisms, this framework enables surprisingly rich interactions.