COMPASS: Rotational Keyboard on Non-Touch Smartwatches.

Entering text is very challenging on smartwatches, especially on non-touch smartwatches where virtual keyboards are unavailable. In this paper, we designed and implemented COMPASS, a non-touch bezel-based text entry technique. COMPASS positions multiple cursors on a circular keyboard, with the location of each cursor dynamically optimized during typing to minimize rotational distance. To enter text, a user rotates the bezel to select keys with any nearby cursors. The design of COMPASS was justified by an iterative design process and user studies. Our evaluation showed that participants achieved a pick-up speed around 10 WPM and reached 12.5 WPM after 90-minute practice. COMPASS allows users to enter text on non-touch smartwatches, and also serves as an alternative for entering text on touch smartwatches when touch is unavailable (e.g., wearing gloves).