AnkleType: A Hands- and Eyes-free Foot-based Text Entry Technique in Virtual Reality

TL;DR

AnkleType is a novel VR text entry method using ankle gestures, enabling hands- and eyes-free typing with comparable speeds to traditional methods, suitable for standing and sitting scenarios.

Contribution

This work introduces AnkleType, the first ankle-based gesture system for eye-free text entry in VR, optimized through user studies and designed for both sitting and standing use.

Findings

Average typing speed of 16.70 WPM with BPSit in visual condition

Average typing speed of 12.87 WPM with BPSit in eyes-free condition

Supports effective hands- and eyes-free text entry in VR environments.

Abstract

Virtual Reality (VR) emphasizes immersive experiences, while text entry often requires hands or visual attention, which may disrupt the interaction flows in VR. We present AnkleType, a hand- and eye-free text-entry technique that leverages ankle-based gestures for both standing and sitting situations. We began with two preliminary studies: one investigated the movement range of users' ankles, and the other elicited user-preferred ankle gestures for text-entry-related operations. The findings of these two studies guided our design of AnkleType. To optimize AnkleType's keyboard layout for eye-free input, we conducted a user study to capture the users' natural ankle spatial awareness with a computer-simulated language test. Through a pairwise comparison study, we designed a bipedal input strategy for sitting (BPSit) and a unipedal input strategy for standing (UPStand). Our first in-VR text-entry evaluation with 16 participants demonstrated that our methods could support the average typing speed from 8.99 WPM (BPSit) to 9.13 WPM (UPStand) for our first-time users. We further evaluated our design with a 7-day longitudinal study with twelve participants. Participants achieved an average typing speed of 15.05 WPM with UPStand and 16.70 WPM with BPSit in the visual condition, and 11.15 WPM and 12.87 WPM, respectively in the eyes-free condition.