Augmenting Pinch Selection Using Smart Ring Vibration Feedback for Extended Reality Interaction: Perceptual Analysis and Guidelines

The rise of extended reality technologies has elevated the importance of seamless and natural haptic feedback, particularly for bare-hand interactions. To this end, a ring-type form factor can offer an effective solution. In this paper, we investigate the perceptual space and key perceptual dimensions of vibrotac-tile feedback applied on the palmar side of the proximal phalanx of the index finger using a ring-shaped device during a two-finger pinch selection task—a widely used interaction technique in XR. A total of 37 feedback conditions were designed, comprising 36 vibration patterns that varied in frequency, amplitude, envelope shape, and duration and a no-feedback baseline condition. Two perceptual experiments were conducted. In Experiment 1, a perceptual space was constructed to visualize the relationships between different feedback sensations. The estimated space had two dimensions, and the sensations were differentiated mostly by the frequency and perceived intensity. In Experiment 2, we identified perceptual dimensions within the perceptual space constructed in Experiment 1 by evaluating the sensations using seven bipolar adjective pairs. The space was best explained using trivial-consequential and dull-crisp dimensions. Our findings contribute to understanding how vibrotactile feedback augments pinching sensations and provide design guidelines for smart ring vibrotactile feedback.