More than just a pretty face: conversational protocols and the affordancesof embodiment

Prior research into embodied interface agents has found that users like the m and find them engaging. However, results on the effectiveness of these in terfaces for task completion have been mixed. In this paper, we argue that embodiment can serve an even stronger function if system designers use actu al human conversational protocols in the design of the interface. Communica tive behaviors such as salutations and farewells, conversational turn-takin g with interruptions, and describing objects using hand gestures are exampl es of protocols that all native speakers of a language already know how to perform and can thus be leveraged in an intelligent interface. We discuss h ow these protocols are integrated into Pea, an embodied, multi-modal interf ace agent who acts as a real-estate salesperson, and we show why embodiment is required for their successful implementation. (C) 2001 Elsevier Science B.V. All rights reserved.