Understanding the Design Space of Mouth Microgestures

TL;DR

This paper explores the design space and usability of mouth microgestures for wearable devices, identifying a practical gesture set and providing guidelines for intuitive face-based interactions.

Contribution

It systematically investigates user preferences and usability of mouth gestures, creating a taxonomy and practical set for future wearable device interactions.

Findings

Identified 14 natural and easy-to-perform mouth gestures

Developed a taxonomy for mouth gestures

Provided design guidelines for mouth-based interactions

Abstract

As wearable devices move toward the face (i.e. smart earbuds, glasses), there is an increasing need to facilitate intuitive interactions with these devices. Current sensing techniques can already detect many mouth-based gestures; however, users' preferences of these gestures are not fully understood. In this paper, we investigate the design space and usability of mouth-based microgestures. We first conducted brainstorming sessions (N=16) and compiled an extensive set of 86 user-defined gestures. Then, with an online survey (N=50), we assessed the physical and mental demand of our gesture set and identified a subset of 14 gestures that can be performed easily and naturally. Finally, we conducted a remote Wizard-of-Oz usability study (N=11) mapping gestures to various daily smartphone operations under a sitting and walking context. From these studies, we develop a taxonomy for mouth gestures, finalize a practical gesture set for common applications, and provide design guidelines for future mouth-based gesture interactions.