Trends & Controversies: Mixed-initiative interaction

James F. Allen, University of Rochester Mixed-initiative interaction is a key aspect of effective human-computer interaction and has great potential to affect work on multiagent systems. The term mixed-initiative interactionis sometimes conflated with human-computer interaction itself, but this is a mistake because almost all models of HCI so far are not mixedinitiative, and mixed-initiative systems need not involve a human. It is perhaps in HCI where we will see the greatest impact. The development of mixed-initiative intelligent systems will ultimately revolutionize the world of computing even more than the recent move to GUIs, in my view. This essay describes the goals of research in mixed-initiative interaction, suggests a general framework for thinking about work in the area based on the properties of human dialogue, and then briefly describes the key problems to overcome before mixed-initiative systems become a reality. For simplicity, I will focus on a single scenario consisting of two agents: a human and an intelligent system. Mixed-initiative interaction can occur in many other scenarios as well, including between multiple machines cooperating to perform tasks (such as in distributed planning) or between multiple people and machines interacting to coordinate their activities (collaboration systems, for example). Most everything I say here generalizes to these other cases. In fact, many of the issues become even more crucial as the number of agents grows. In many examples, I will draw from our experience in building mixed-initiative planning systems over the last five years. 1–3.