Modern video games often feature moving target acquisition (MTA) tasks, where users must press a button when a moving target reaches an acquisition line. User performance models in MTA are useful for quantitative skill analysis and computational game level design, but have so far been constructed only for cases where there is a single lane for a target to appear and follow. In this study, the first user performance model is presented and validated for an MTA task with multiple lanes. The model is built as an integration of the existing MTA model and the drift-diffusion model, a model of human decision-making process under time-pressure. In a user study, we showed that the model can fit lane recognition error rates and input timing distributions with significantly higher coefficients of determination ($R^2$) and accuracy than a baseline model.
Eye movements provide a window into human behaviour, attention, and interaction dynamics. Challenges in real-world, multi-person environments have, however, restrained eye-tracking research predominantly to single-person, in-lab settings. We developed a system to stream, record, and analyse synchronised data from multiple mobile eye-tracking devices during collective viewing experiences (e.g., concerts, films, lectures). We implemented lightweight operator interfaces for real-time-monitoring, remote-troubleshooting, and gaze-projection from individual egocentric perspectives to a common coordinate space for shared gaze analysis. We tested the system in a live concert and a film screening with 30 simultaneous viewers during each of two public events (N=60). We observe precise time-synchronisation between devices measured through recorded clock-offsets, and accurate gaze-projection in challenging dynamic scenes. Our novel analysis metrics and visualizations illustrate the potential of collective eye-tracking data for understanding collaborative behaviour and social interaction. This advancement promotes ecological validity in eye-tracking research and paves the way for innovative interactive tools.
In networked applications, latency can disrupt the sense of synchrony by causing offsets e.g. between local speech and remote visual response. We investigate the influence of frequency and Stimulus Onset Asynchrony (SOA) on synchrony perception during rhythmic audiovisual experiences. Our results show that the Point of Subjective Synchrony (PSS) is influenced by frequency, whereas the Window of Subjective Synchrony (WSS) is not. Variations in SOA induce adaptive gaze behavior in response to audiovisual latencies, while pupil diameter increases with increasing SOA, suggesting a higher cognitive load for successive unisensory rather than integrated events. This has practical implications for the design of computer-mediated applications that promote a sense of community through rhythmic interaction. Eye tracking data may indicate perceived (a)synchrony in audiovisual integration. In addition, the choice of frequencies may help to mask latencies, enhance the experience of synchrony and thus support feelings of closeness and intimacy in virtual interaction.
Pass-through technologies are promising for mixed reality (MR) systems. Therefore, various MR applications operating in pass-through devices emerged in diverse domains, such as education and healthcare. However, research on the everyday use of pass-through devices remains limited, despite it blending real and virtual environments.
This study explores the user experience of pass-through devices in people's daily tasks. We conducted a field study with 16 participants and analyzed data from eight daily tasks. For in-depth analysis, we employed three measures in terms of quantitative, qualitative, and bio-signal. As a result, we found that participants felt differently in terms of immersion, collision anxiety, and workload. Findings suggest that pass-through devices are not yet fully ready for integration into daily life. However, the potential for widespread adoption exists as the technology continues to advance. Finally, we offer guidelines and considerations to improve the usability of pass-through devices for everyday use.
Users hold their mobile phones at varying distances depending on their posture, the application being used, and the task's nature. Without considering such variation when designing UI target sizes limits the applicability of gaze selection for everyday interaction with mobile devices. Towards this end, we conducted a user study (N=24) to investigate the implications of different target sizes and viewing across different screen regions. While larger targets generally improve accuracy and decrease precision, accuracy is significantly higher in the horizontal than in the vertical direction. This subsequently led us to find that increasing the tracking area in the vertical direction only, while maintaining the same visual target size, significantly improves accuracy. This suggests that visually smaller targets with larger vertical tracking areas enhance accuracy. Based on our results, we present concrete design guidelines for developers to optimise target sizes on gaze-enabled mobile devices to improve accuracy across varying user-to-screen distances.
Understanding eye dominance, the subconscious preference for one eye, has significant implications for 3D user interfaces in VR and AR, particularly in interface design and rendering.
Although HCI recognizes eye dominance, little is known about what causes it to switch from one eye to another.
To explore this, we studied eye dominance in VR, where 28 participants manually aligned a cursor with a distant target across three tasks.
We manipulated the horizontal viewing angle, the hand used for alignment, and eye movement induced by target behaviour.
Our results confirm the dynamic nature of eye dominance, though with fewer switches than expected and varying influences across tasks.
This highlights the need for adaptive HCI techniques, which account for shifts in eye dominance in system design, such as gaze-based interaction, visual design, or rendering, and can improve accuracy, usability, and experience.
Smartphones support diverse inputs, however, the multitude of devices and platforms makes it challenging for people to discover when and where interactions are meaningful.
Motivated by the effectiveness of visual signifiers in communicating interactivity, we explore the viability of integrating temporary visual signifiers in animated transitions between UI screens to promote the discoverability of swipe-revealed widgets. We implemented two transition types (Container Transform, Panels), and compared them to a baseline. We found that transitions with a standard duration did not impact the discovery of swipe-related widgets (N=33). We ran a follow-up study (N=22) with extremely slow 5000ms transitions to guarantee noticeability, but similarly found no impact on discovery of swipe-revealed widgets, diverging from previous findings for visual signifiers.
This raises interesting questions about the perception and understanding of interaction signifiers, and indicates a disconnect between noticeability and discoverability, while highlighting difficulties with adapting established interface elements beyond their entrenched functionality.