Controllers or Bare Hands? A Controlled Evaluation of Input Techniques on Interaction Performance and Exertion in...

Area of Science:

• Human-Computer Interaction
• Virtual Reality Systems
• Ergonomics

Background:

• Traditional Virtual Reality (VR) interfaces rely on controllers for mid-air interaction.
• Emerging VR systems use cameras for hand tracking, enabling controller-free interaction.
• The comparative effectiveness of controller-based versus free-hand VR interaction remains unclear.

Purpose of the Study:

• To investigate the impact of VR input modality (controller vs. free-hand) on user performance and experience.
• To compare controller-based and free-hand interaction across different mid-air techniques (touch, raycast) and tasks (selection, trajectory-tracing).
• To analyze the relationship between physical exertion, task performance, and user agency in VR.

Main Methods:

• Comparative study evaluating controller-based and free-hand VR interaction modalities.
• Inclusion of two mid-air interaction techniques: touch and raycasting.
• Assessment of physical exertion, task performance (speed, accuracy), user agency, and motor behavior.

Main Results:

• Participants using VR controllers reported less physical exertion, higher agency, and achieved greater speed and accuracy in raycast settings.
• User preference varied: VR controllers were favored for raycasting, while free-hand interaction was preferred for touch-based tasks.
• Increased physical exertion correlated with faster selection, more arm motion, motion speed variation, poor posture, and decreased agency and accuracy.

Conclusions:

• VR controllers may offer superior performance and comfort for specific mid-air interaction techniques like raycasting.
• Free-hand interaction shows promise for touch-based VR interfaces, aligning with user preference.
• Ergonomic factors and user agency are significantly influenced by VR input modality and interaction design.