User capabilities in eyes-free spatial target acquisition in immersive virtual reality environments

Area of Science:

• Human-Computer Interaction
• Virtual Reality
• Usability Engineering

Background:

• Immersive virtual reality (VR) relies heavily on visual input for object search.
• Limited field of view (FOV) in head-mounted displays (HMDs) necessitates frequent head turning, reducing interaction efficiency and user experience.
• Eyes-engaged interaction in VR can be a bottleneck for seamless user interaction.

Purpose of the Study:

• To systematically investigate user capabilities in eyes-free spatial target acquisition within VR.
• To identify optimal target locations considering horizontal and vertical angles, distance, and body side.
• To provide design guidelines for arranging targets in VR for eyes-free interaction.

Main Methods:

• Users performed spatial target acquisition tasks in an immersive VR environment without visual guidance.
• Systematic variation of target locations based on horizontal angles, vertical angles, distances, and body sides.
• Measurement of acquisition accuracy and task load to evaluate user performance.

Main Results:

• High acquisition accuracy and low task load were observed for targets at front and middle horizontal angles, and middle vertical angles.
• No trade-off between acquisition accuracy and task load was found for targets at long distances.
• Acquisition accuracy and task load varied significantly depending on the body side.

Conclusions:

• User performance in eyes-free target acquisition is angle and distance-dependent within VR.
• Designers should consider specific spatial arrangements to optimize eyes-free interaction in VR.
• Findings offer practical guidelines for enhancing VR user experience by optimizing target placement for eyes-free interaction.