Dialog-based technologies play an ever-increasing role in our lives. The interest in conversational interfaces stems not only from their importance for universal access, but also because they can be used in settings in which traditional hands-on interface devices are not practical. Efforts are underway to extend the use of dialog systems into new roles, including: becoming companions to help seniors remain independent; moving some aspects of healthcare outside of the clinical setting; providing entertainment and interactive theater experiences; and improving disaster response. In many of these systems, the computer conversational partner is presented as a talking head or graphical persona. Although designers of dialog systems aim to make them simple and natural to use, major gaps in our understanding of human-computer interaction create obstacles to achieving this goal.
Some of these gaps are likely to be filled by examining recent psycholinguistic models of human conversational interaction. These models explore the time-course with which information coming from the context of conversation affects language processing. This context includes the shared information, or common ground, between interlocutors, as well as the processes by which reference to items in common ground is coordinated. One property of negotiated reference concerns the establishment of conceptual pacts, which are a (usually implicit) agreement to refer to an item in common ground from the same conceptual perspective. Recent psycholinguistic findings have examined whether conceptual pacts in conversation are speaker-specific, and how quickly this information is used during comprehension. To the extent that speaker-specific conceptual pacts have significant and immediate effects on the interpretation of reference in human-human interaction, dialog systems utilizing computer-based partners should take these characteristics into account in human-computer interaction.
