Effective Visualization of Time-Critical Notifications in Virtual Reality

Abstract

Virtual Reality (VR) devices empower users to be fully immersed into a virtual environment. However, time-critical notifications must be perceived as quickly and correctly as possible. Especially, if they indicate risk of injury (e.g., bumping into walls). Compared to displays used in previous work to investigate fast response times, immersion into a virtual environment, wider field of view and use of near-eye displays observed through lenses may have a considerable impact on the perception of time-critical notifications. Therefore, we studied the effectiveness of different visualization types (color, shape, size, text, number) in two different setups (room-scale, standing-only) with 20 participants in VR. Out study consisted of a part were we tested one notification and a part with multiple notifications showing up at the same time. We measured reaction time, correctness and subjective user evaluation. Our results showed that visualization types can be organized by consistent effectiveness ranking for different numbers of notification elements presented. Further, we offer promising recommendations regarding which visualization type to use in future VR applications for showing time-critical notifications.