ThumbText: Text Entry for Wearable Devices Using a Miniature Ring

Users can benefit from using an auxiliary peripheral that could mitigate many concerns with direct text entry on wearable devices. We introduce ThumbText, a thumb-operated text entry approach for a ring-sized touch surface. Through a multi-part exploration, we first identify a suitable discretization of the miniature touch surface for thumb input. We then design a number of two-step selection techniques for supporting the input of at least 28 characters. On a miniature touch surface, we find that a continuous touch-slide-lift selection technique in a 2×3 grid discretization offers improved performance gains over other selection methods. Finally, we evaluate ThumbText against techniques also designed for wearable devices and find that ThumbText allows for higher text entry rates than SwipeBoard and H4-Writer.