GuidingBand: Evaluating Speed, Precision and Accuracy of a Vibrotactile Hand Guidance System

Abstract

Abstract Computerized tactile guidance systems can potentially help in human visual perception tasks such as identifying a desired object in a collection of similar objects. We designed a wrist-wearable tactile guidance system called GuidingBand that provides vibrational cues to help the user pick visual targets out of an array. We conducted three studies to systematically investigate the interplay of machine-led tactile guidance and human visual perception. The studies involve presenting visual targets to users on a screen and giving them visual search tasks. In Study 1, we identified the error rate of our guidance system. We presented participants (N=20) with arrays of identical, square targets to pick from, progressively reduced the target sizes and evaluated error rates for each size. Notably, we observed a 4% error rate at a target size of 10 mm. In Study 2, we compared the error rate of the guidance system with and without the help of human visual perception in a visual search task. We constructed a task that involved showing users an array of distractor rectangles (set sizes 2 to 10) varying only in length and asked them to identify the correct target that was previously shown to them. Participants (N=13) had fewer errors when they tried to identify targets with tactile guidance alone, followed by guidance and perception combined and perception alone. In Study 3, we had the same task as Study 2 but the distractor set sizes were larger (varying from 4 to 28), we had more participants (N=30) and measured errors and task time. While perception alone was the fastest, it was also the most error prone. The combined mode was faster and less error prone than guidance only mode, as expected, indicating that human–computer collaboration yielded the best performance.