Differences in Fitts' Law Task Performance Based on Environment Scaling

Haptics research has begun implementing haptic feedback in tasks of great precision and skill, such as robotic surgery. Haptic displays can represent task environments with arbitrary scaling. Fitts’ Law suggests differences in the scale of a workspace rendered on a visual display and in a haptic display should not affect performance of those tasks. However, interactions of great precision and skill may require understanding and verifying the influence of perceiving an environment when the visual and haptic displays represent those environments with differing scales. This experiment measured the influence that mismatched haptic and visual display scalings had on movement times in. Each of five treatments used different scales in the visual and the haptic displays. A Friedman rank test showed a significant difference across all treatments. A post hoc pairwise comparison showed a nearly significant difference between two treatments. These findings suggest the need for further study using more participants and parametric statistics to measure the magnitude of the possible influences.