Investigating haptic assistive interfaces for motion impaired users: force-channels and competitive attractive-basins

Following a pilot study that suggested that force-feedback gravity wells could, under certain conditions, lead to 20- 50% improvements in time to target in a selection task, a series of experiments further investigated the potential for enhancement of user interfaces for disabled computer users by the use of haptic feedback modulated on the basis of cursor position. Two experiments are reported examining (1) the effect of size of attractive basins in adjacent targets on time to target in a point and click selection task and (2) the effect of presence of four different types of forcefeedback channels between start point and target on times to select a target. It was found that the presence of adjacent attractive basins was not disruptive of navigation to target, and that haptic force channels may only decrease times for those with high degrees of impairment. Cursor trace analysis suggested that the increased attraction force and range counteracts the disruptive effect of inappropriate cursor capture for the overlapping basins and that inappropriate ballistic movements were suppressed by channels for some of the impaired users but that channels may have had no effect on overshoot errors in these cases