Investigating Haptic Assistive Interfaces for Motion-impaired Users: Force-channels and Competitive Attractive-basins

Abstract

Following a pilot study that suggested that force-feedback
\ngravity wells could, under certain conditions, lead to 20-
\n50% improvements in time to target in a selection task, a
\nseries of experiments further investigated the potential for
\nenhancement of user interfaces for disabled computer users
\nby the use of haptic feedback modulated on the basis of
\ncursor position. Two experiments are reported examining
\n(1) the effect of size of attractive basins in adjacent targets
\non time to target in a point and click selection task and (2)
\nthe effect of presence of four different types of forcefeedback
\nchannels between start point and target on times
\nto select a target. It was found that the presence of adjacent
\nattractive 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.