Selecting While Walking: An Investigation of Aiming Performance in a Mobile Work Context

Computing devices are becoming more ubiquitous and are increasingly used in environments away from the desktop. For example, computers are more frequently being used while walking, as is the case with hand-held devices, navigation systems and mobile phones. This paper investigates selection accuracy and task completion time when using stylus touch as the input method on hand-held devices. An experiment is described that measures the effect of walking slowly during interactions. Fitts’ law was found to be an effective predictor of task completion time. Furthermore, walking did not have a significant negative effect on task completion time, although an increase in error rate and spatial variability of selection endpoints was discovered. Based on these findings, stylus touch is an acceptable input method for interactive systems that are used in non-stationary environments provided that interface layout is designed to compensate for increased errors and reduced selection accuracy.