In virtual reality (VR) experiences, mismatches between reality and virtuality are usually undesirable, as they can disrupt immersion and induce cybersickness. However, when carefully controlled, they may expand the design space of VR. This research investigates perceptual detection thresholds for mismatches between real and virtual inclinations during cycling in VR. Using a custom simulation, N = 30 participants cycled through a virtual city while physical and visual inclinations were independently manipulated. Real inclinations were implemented with a tilting indoor bike, providing vestibular and proprioceptive feedback, while virtual inclinations within the simulated environment were presented visually. A multiple staircase procedure derived estimates for perceptual thresholds that approximate which mismatches in visual and physical inclination were still perceived as congruent. These thresholds reveal a window of perceived congruence before mismatches become noticeable to users. These findings advance understanding of sensory integration in VR cycling and inform applications in immersive training, exergames, and rehabilitation systems.

In the context of rising sedentary lifestyles, this paper investigates the efficacy of "Situated Artifacts"in promoting physical activity. We designed two artifacts that display users' physical activity data within their homes - one physical and one digital. We conducted a 9-week, counterbalanced, within-subject field study with N = 24 participants to assess the impact of these artifacts on physical activity, reflection, and motivation. We collected quantitative data on physical activity and administered daily and weekly questionnaires, employing individual Likert items and standardized instruments, as well as conducted interviews post-prototype usage. Our findings indicate that while both artifacts act as reminders for physical activity, the physical artifact was superior in terms of user engagement. The study revealed that this can be attributed to the higher perceived presence and, thereby, enhanced social interaction, which acts as a motivational source for activity. In this sense, situated artifacts gently nudge toward sustainable health behavior change.

Gait is a distinctive behavioral trait, yet its vulnerability against imitation remains underexplored in immersive environments. We present a study investigating how real-time visual feedback in virtual reality (VR) influences a person’s ability to mimic another’s gait. Through two experiments, we first identify the most usable feedback design (N = 8), then evaluate its impact on imitation performance compared to a baseline without feedback (N = 18). We analyze positional and rotational similarity between participants and target avatars, examining the influence of avatar–user gender matching and repeated practice. Our findings reveal that visual feedback significantly improves rotational alignment and that practice leads to measurable improvements in mimicry accuracy. We discuss implications for avatar embodiment, personalization in VR applications, and potential considerations for behavioral biometric systems. We also contribute a publicly available dataset of gait mimicry in VR, supporting further research on motion learning and imitation.

Virtual mirrors displaying weight changes can support users in forming healthier habits by visualizing potential future body shapes. However, these often come with privacy, feasibility, and cost limitations. This paper introduces the Magic Mirror, a novel distortion-based mirror that leverages curvature effects to alter the appearance of body size while preserving privacy. We constructed the Magic Mirror and compared it to a video-based alternative. In an online study ( N =115), we determined the optimal parameters for each system, comparing weight change visualizations and manipulation levels. Afterward, we conducted a laboratory study ( N =24) to compare the two systems in terms of user perception, motivational potential, and willingness to use daily. Our findings indicate that the Magic Mirror surpasses the video-based mirror in terms of suitability for residential application, as it addresses feasibility concerns commonly associated with virtual mirrors. Our work demonstrates that mirrors that display weight changes can be implemented in users’ homes without any cameras, ensuring privacy.

The global COVID-19 pandemic created a constant need for hand disinfection. While it is still essential, disinfection use is declining with the decrease in perceived personal risk (e.g., as a result of vaccination). Thus this work explores using different visual cues to act as reminders for hand disinfection. We investigated different public display designs using (1) paper-based only, adding (2) screen-based, or (3) projection-based visual cues. To gain insights into these designs, we conducted semi-structured interviews with passersby (N=30). Our results show that the screen- and projection-based conditions were perceived as more engaging. Furthermore, we conclude that the disinfection process consists of four steps that can be supported: drawing attention to the disinfection station, supporting the (subconscious) understanding of the interaction, motivating hand disinfection, and performing the action itself. We conclude with design implications for technology-supported disinfection.