Time-out in mobile text input: The effects of learning and feedback

Abstract

In many user interfaces with restricted input/output capabilities, a time-out is used to automatically change the UI from one mode into another. In this paper we studied the learning of time-outs and the effect of feedback on it in mobile phone text entry. The effects of three different feedback schemes (auditory/visual/no feedback) on learning of two different time-out lengths were compared. We measured the response time from the time-out occurrence to the time of user's reaction. Error rates and the development of the response times in different schemes were used as measures of learning. We also studied if the users learned to estimate the time-out lengths, or if they just reacted to the available feedback. There, were three main findings. Without feedback, response times had great variation. Auditory feedback enabled faster response times than visual. Finally, we found evidence of short-term learning, but not as much of a lasting effect. © Springer-Verlag Berlin Heidelberg 2003.