Pressure-based text entry for mobile devices

This paper describes the design and evaluation of a touch screen-based pressure keyboard to investigate the possibilities of pressure as a new method of input for mobile devices. A soft press on the touchscreen generated a lowercase letter, a hard press an uppercase one. The aim was to improve input performance when entering mixed-case text, or shifted characters often used for emoticons, etc. An experiment compared two different forms of pressure input (Dwell and Quick Release) against a standard shift key keyboard, with users both sitting and walking. Results showed that Quick Release was the fastest for input of mixed case text with Dwell being the most accurate, even when users were mobile. The results demonstrate that pressure input can outperform a standard shift-key keyboard design for mobile text entry.