Dwell plus : Multi-Level Mode Selection Using Vibrotactile Cues

Abstract

We present Dwell+, a method that boosts the effectiveness of typical dwell selection by augmenting the passive dwell duration with active haptic ticks which promptly drives rapid switches of modes forward through the user's skin sensations. In this way, Dwell+ enables multi-level dwell selection using rapid haptic ticks. To select a mode from a button, users dwell-touch the button until the mode of selection is haptically prompted. Our haptic stimulation design consists of a short 10ms vibrotacile feedback that indicates a mode arriving and a break that separates consecutive modes. We first tested the effectiveness of 170ms, 150ms, 130ms, and 110ms intervals between modes for a 10-level selection. The results reveal that 3-beats-per-chunk rhythm design, e.g., displaying longer 25ms vibrations initially for all three modes, could potentially achieve higher accuracy. The second study reveals significant improvement wherein a 94.5% accuracy was achieved for a 10-level Dwell+ selection using the 170ms interval with 3 beats-per-chunk design, and a 93.82% rate of accuracy using the more frequent 150ms interval with similar chunks for 5 level selection. The performance of conducting touch and receiving vibration from disparate hands was investigated for our final study to provide a wider range of usage. Our applications demonstrated implementing Dwell+ across interfaces, such as text input on a smartwatch, enhancing touch space for HMDs, boosting modalities of stylus-based tool selection, and extending the input vocabulary of physical interfaces.