Abstract
This study examines the effects of visual and tactile feedback on fine positioning tasks. Two experiments were performed in which a caliper's slider is positioned using a thumb. In Experiment 1, the comparison between analog and digital displays of the slider's position was made to investigate the influence of the visual feedback. The movement time in the task using the analog display is smaller than that of digital. In Experiment 2, positioning resolution is varied from 1.0 to 0.01mm to get the influence of the tactile feedback. In case of high resolution, the movement time becomes large and the variance among subjects also becomes large. According to the analysis with slider's time-movement curves, which are divided into course and fine positioning phases, the visual feedback is effective at the fine positioning phase and the tactile feedback is effective both for an early stage of the course positioning and for the fine positioning. Especially, the ability for smooth coordination between the tactile feedback and the thumb movement at the fine positioning phase is found to be essential, and to be evaluated by the movement-time's dissociation from the Fitts' Law.
