Room-scale locomotion in VR can promote physical movement to combat the negative effects of a sedentary lifestyle. Therefore, it is useful to investigate factors which may motivate users to walk instead of teleport. In a within-subjects study with 24 participants, we investigated the effects of avatar appearance and target distance on users' locomotion behavior, when given the option to either walk or teleport. In particular, we manipulated three aspects of avatar appearance-body completeness (full-body vs upper-body only), body weight (normal vs obese), and clothing (casual vs superhero armor), and we provided three target distances (1.5 meters, 3.0 meters, and 4.5 meters). We found that avatar obesity decreased willingness to walk, but only for full-body avatars. We also found that close target distances encouraged more walking than teleporting, up to a certain threshold distance. Additionally, we found that users' perceived similarity to their avatar correlated with their willingness to walk. Our findings can be applied to motivate users to walk more in VR, such as in VR exergames.

According to Hall’s theory, the space individuals maintain between one another depends on relational closeness and situational context. Prior research suggests that interpersonal distance (IPD) varies not only between virtual and real humans, but also among virtual humans depending on their perceived agency. However, little is known about how people spatially negotiate entry into mixed groups comprising different types of agents in extended reality (XR) settings. In this study, we examine participants’ entry behavior as they join a circular F-formation composed of three distinct entities: an agent, an avatar, and a real human. Specifically, we investigate how participants position themselves relative to each entity, analyzing their preferences and behaviors in terms of IPD and entry dynamics. Our findings reveal that participants maintained the greatest IPD from the real human, followed by the avatar and the agent, suggesting nuanced social distinctions among these three entities. Furthermore, when the real human was absent, participants tended to maintain a greater distance from the avatar compared to the agent. These results offer valuable insights for the design of XR collaboration environments and for understanding social dynamics in multi-agent interactions.

Embodied conversational agents (ECAs) capable of non-verbal behaviors have been developed to address the limitations of voice-only assistants, with research exploring their use in mixed and augmented reality (AR), suggesting they may soon interact with us more naturally in physical spaces. Traditionally, AI voice assistants are activated through wake-up keywords, and since they are invisible, their method of appearance has not been a concern. However, for ECAs in AR, the question of how they should enter the user's space when summoned remains underexplored. In this paper, we focused on the plausibility of ECAs' entering action into the user's field of view in AR. We analyzed its impact on user experience, concentrating on perceived social presence and co-presence of the agent. Three entrance styles were chosen for comparison: an obviously impossible one, a possible one, and an intermediate one, alongside a voice-only condition. We designed and conducted a within-subjects study with 38 participants. Our results indicated that while the plausibility of the action had less impact on functionality compared to the embodiment itself, it significantly affected social/co-presence. These findings highlight the importance of entrance design for future AR agent experiences.

The demand to utilize digital humans for conversation systems in multiple areas has increased. Time delays in a conversation with digital humans can be occurred because of network and natural language processing, which can deteriorate the users’ satisfaction and the availability of the digital humans. In this study, we designed a gestural filler that can be exhibited when delay occurs during a conversation with a digital human, and compared the effects of the gestural filler with conversational filler.