Probabilistic touchscreen keyboard incorporating gaze point information

We propose a novel probabilistic keyboard that takes into account the distance between a gaze point and a touch position in order to improve typing efficiency. The proposed keyboard dynamically changes the size of the search space for predicting candidate words based on a model that estimates the magnitude of touch position errors according to the distance between the gaze point and the touch position. This makes it possible for users to type intended words even when they glance at different areas on the screen. Performance was evaluated in terms of input accuracy in total error rate (TER) and of typing speed in words per minute (WPM). The results showed that the proposed keyboard successfully reduced the TER by 18.2% and increased WPM by 12.7% compared to the conventional keyboard.