Understanding the Effect of Latency on User Performance of Target Selection in Virtual Reality

Area of Science:

• Human-Computer Interaction
• Virtual Reality
• Usability Engineering

Background:

• High latency in virtual reality (VR) systems is a significant challenge, stemming from hardware limitations and computational demands.
• Latency negatively impacts user performance, particularly in fundamental interaction tasks like target selection, though behavioral mechanisms are not fully understood.
• Existing research confirms latency's detrimental effects on selection times and success rates in 2D systems.

Purpose of the Study:

• To investigate the effects of latency on target selection performance in VR using controller-based raycasting and bare-hand direct touch.
• To elucidate the behavioral mechanisms underlying latency's impact on selection times, success rates, and endpoint distributions.
• To develop and validate novel mathematical models that accurately predict performance under varying latency conditions.

Main Methods:

• Conducted a user study (N=31) to collect data on selection times, success rates, and endpoint distributions across different latency levels for two VR selection methods.
• Developed two new mathematical models incorporating latency, target width, and movement amplitude for each selection method.
• Validated the proposed models using data from a second user study (N=16).

Main Results:

• Latency significantly affects user performance in VR target selection, with distinct behavioral patterns observed between controller-based raycasting and direct touch.
• Two novel mathematical models were developed, accurately accounting for latency, target width, and movement amplitude.
• The newly developed models demonstrated superior performance compared to existing models in predicting user interaction outcomes.

Conclusions:

• The developed mathematical models provide a more accurate understanding of latency's impact on VR selection tasks.
• Actionable recommendations are provided for VR interface design to mitigate latency's negative effects and enhance user experience.
• Findings contribute to the optimization of VR interactions, particularly in latency-sensitive applications.