View - ResearchGate

Party Hosts and Tour Guides 47conversation (Cassell), to indicate who they are referring to, or who might knowmore about a topic, and to help delineate conversational sub-groups within themain group (Clark, Hall).To design a successful agent for this context, I believe there are several designfactors to keep in mind:It’s important that the agent ’knows’ when to take the floor, and whatvalue it might have when it does, as well as when to give up the floor.The agent should use proper turn-taking cues, and demonstrate sensitivityto facilitating the overall social flow of the conversation, rather thanfocussing on modelling or adapting to any one person.The agent should have a clear and appropriate social role, such as host orguide (see Isbister and Hayes-Roth for a demonstration of the effectivenessof an agent’s social role in influencing visitor behavior).In the sections that follow, I describe two interface agent projects which incorporatedgroup-focused nonverbal social cue tracking and expression. Pleasesee the acknowledgements section of this paper for a list of contributors to thisresearch.2. Helper Agent2.1 Design of Helper AgentHelper Agent supports human-human conversations in a video chat environment.Users have avatars they can move freely around the space, and HelperAgent is an animated, dog-faced avatar, which spends most of its time listening,at a distance. The agent tracks audio from two-person conversations, lookingfor longer silences. When it detects one, it approaches, directs a series oftext-based, yes/no questions to both people, and uses their answers to guide itssuggestion for a new topic to talk about. Then the agent retreats until neededagain (see Figure 1).Because Helper Agent is presented on-screen the same way users are, wecould use nonverbal cues, such as turning to face users as it poses a questionto them, and approaching and departing the conversation physically. The animationsinclude nonverbal cues for asking questions, reacting to affirmative ornegative responses, and making suggestions. The dog orients its face toward theuser that it is addressing, with the proper expression for each phase: approach,first question, reaction, follow-up question, and finally topic suggestion. Afterconcluding a suggestion cycle, the agent leaves the conversation zone, andmeanders at a distance, until it detects another awkward silence. This makesit clear to the conversation pair that the agent need not be included in theirdiscussion.