Don't walk between us: adherence to social conventions when joining a small conversational group of agents.

When modeling life-like Embodied Conversational Agents (ECAs), conveying politeness through verbal and nonverbal behaviors with persuasive intents is a significant challenge, as it underlies the conventional set of behavioral rules that govern human communication. In the present study, we explore the adherence to such rules in the context of joining a small, freestanding conversational group of agents in VR. In particular, we focus on the behavior adopted by participants while walking towards the agents, and on whether ECAs were treated in the same way human agents normally are. 45 test subjects were invited by an ECA to walk towards the group by applying one of six possible politeness strategies; after freely joining the group, they were asked to rate the agent's politeness according to four distinct aspects (Clarity, Face loss, Positive face, and Negative face). Across all strategies, in 48% of the trials participants were successfully persuaded to join the group at an inconvenient location. Out of those trials, participants adhered to social conventions by not crossing the convex empty space between the group members (o-space) in 75% of them on average. Additionally, analysis of verbal and nonverbal behaviors in ECAs shows that direct request strategies are more effective than indirect ones, although in some cases they may be perceived as less polite.