A Thumb Stroke-Based Virtual Keyboard for Sight-Free Text Entry on Touch-Screen Mobile Phones

Abstract

The use of QWERTY on most of the current mobile devices for text entry usually requires users' full visual attention and both hands, which is not always possible due to situational or physical impairments of users. Prior research has shown that users prefer to hold and interact with a mobile device with a single hand when possible, which is challenging and poorly supported by current mobile devices. We propose a novel thumbstroke based keyboard called ThumbStroke, which can support both sight-free and one-handed text entry on touch-screen mobile devices. Selecting a character for text entry via ThumbStroke completely relies on the directions of thumb movements at anywhere on a device screen. We evaluated ThumbStroke through a longitudinal lab experiment including 20 sessions with 13 participants. ThumbStroke shows advantages in typing accuracy and user perceptions in comparison to Escape and QWERTY and results in faster typing speed than QWERTY for sight-free text entry.

CameraKeyboard: A Novel Interaction Technique for Text Entry Through Smartphone Cameras

“…Some of these techniques, besides reducing the number of keys pressed by grouping multiple letters, are designed to allow sight-free text entry. Two examples are ThumbStroke [14] and Escape-Keyboard [15]: the former is a virtual keyboard with a single round key in which each letter is located in one of eight areas, and the latter shows four areas where users can perform touches-and-flicks in eight different directions to select a letter.…”