Exploring tilt-based text input for mobile devices with teenagers

Most modern tablet devices and phones include tilt-based sensing but to-date tilt is primarily used either for input with games or for detecting screen orientation. This paper presents the results of an experiment with teenage users to explore a new tilt-based input technique on mobile devices intended for text entry. The experiment considered the independent variables grip (one-handed, two-handed) and mobility (sitting, walking) with 4 conditions. The study involved 52 participants aged 11-16 carrying out multiple target selection tasks in each condition. Performance metrics derived from the data collected during the study revealed interesting quantitative findings, with the optimal condition being sitting using a two-handed grip. While walking, task completion time was 22.1% longer and error rates were 63.9% higher, compared to sitting. Error rate were 31.4% lower using a two-handed grip, compared to a one-handed grip. Qualitative results revealed a highly positive response to target selection performed using the method described here. This paper highlights the potential value of tilt as a technique for text input for teenage users.