The Feasibility of Eyes-Free Touchscreen Keyboard Typing

Keith Vertanen, Haythem Memmi, Per Ola Kristensson

ASSETS '13: Proceedings of the ACM SIGACCESS Conference on Computers and Accessibility (poster), 2013.

Typing on a touchscreen keyboard is very difficult without being able to see the keyboard. We propose a new approach in which users imagine a Qwerty keyboard somewhere on the device and tap out an entire sentence without any visual reference to the keyboard and without intermediate feedback about the letters or words typed. To demonstrate the feasibility of our approach, we developed an algorithm that decodes blind touchscreen typing with a character error rate of 18.5%. Our decoder currently uses three components: a model of the keyboard topology and tap variability, a point transformation algorithm, and a long-span statistical language model. Our initial results demonstrate that our proposed method provides fast entry rates and promising error rates. On one-third of the sentences, novices' highly noisy input was successfully decoded with no errors.