TipText: Eyes-Free Text Entry on a Fingertip Keyboard

In this paper, we propose and investigate a new text entry technique using micro thumb-tip gestures. Our technique features a miniature QWERTY keyboard residing invisibly on the first segment of the user's index finger. Text entry can be carried out using the thumb-tip to tap the tip of the index finger. The keyboard layout was optimized for eyes-free input by utilizing a spatial model reflecting the users' natural spatial awareness of key locations on the index finger. We present our approach of designing and optimizing the keyboard layout through a series of user studies and computer simulated text entry tests over 1,146,484 possibilities in the design space. The outcome is a 2×3 grid with the letters highly confining to the alphabetic and spatial arrangement of QWERTY. Our user evaluation showed that participants achieved an average text entry speed of 11.9 WPM and were able to type as fast as 13.3 WPM towards the end of the experiment.