Effects of variation in system responsiveness on user performance in virtual environments

Area of Science:

• Human-Computer Interaction
• Virtual Reality
• Usability Engineering

Background:

• System responsiveness (SR) is crucial for user experience, defined as the time delay between user input and system reaction.
• SR variability, measured by mean (MSR) and standard deviation (SDSR), significantly influences interactive system performance.
• Virtual environments (VEs) present unique challenges for maintaining optimal SR due to complex rendering and interaction demands.

Purpose of the Study:

• To investigate the impact of SR variability (MSR and SDSR) on user performance in virtual environments.
• To determine the threshold of SDSR that affects grasp and placement task performance.
• To provide guidance for VE designers on managing SR for improved human-computer interaction.

Main Methods:

• Conducted three within-subjects studies with 11, 12, and 10 participants, respectively.
• Experimentally manipulated MSR and SDSR to assess their effects on grasp and placement tasks in VEs.
• Measured user performance metrics related to task completion and accuracy.

Main Results:

• SDSR significantly impacted task performance only when exceeding 82 ms.
• Placement tasks, requiring more frequent visual feedback, were more sensitive to SR fluctuations than grasp tasks.
• MSR did not show a significant impact on performance within the tested ranges.

Conclusions:

• VE designers can tolerate higher SDSR (above 82 ms) without significantly degrading grasp task performance.
• SR control strategies should be tailored to task requirements, particularly the need for visual feedback frequency.
• Findings offer practical insights for optimizing human-computer interfaces in diverse interactive graphical applications.