論文アブストラクト：Making gestures easy for imaging systems to reliably recognize often comes at the expense of user effort. But what is the impact of increasing a gesture's effort, even slightly, on user preference? We investigate physical effort, system reliability, and user satisfaction in two experiments. The first explores eight basic command gestures. Participants preferred the less effortful gestures in two of the three easy-difficult gesture pairs when they perceived the difference in effort to be significantly different. The second experiment explores two separate three-dimensional pointing and selection conditions that differ only in the movement distance required to finish the task. In both experiments, there is a significant negative correlation between a gesture's effort and its appeal. The results show the great impact that effort has on a user's willingness to utilize the system. The findings provide evidence that the trade-off between user effort and system reliability must be carefully considered to build an effective gesture interface.