Effects of Logarithmically Rescaling Display Gain on a Fitts' Law Task

摘要

This study explored a method of reducing movement time for movements over large amplitudes to small widths in a discrete positioning task. The method expanded the displayed target width by exponentially increasing display gain in the area of the target. The study used a first order discrete positioning task and varied screen type, order of presentation, rate of logarithmic approach, and index of difficulty. Movement time and reaction time data were collected, as well as a record of cursor position with time. Relevant measures of performance were abstracted from this record which allowed a complete examination of performance differences. The results showed that no benefit was found due to screen rescaling. The result was attributed to the fact that any benefit accrued by magnifying the area around the target was offset by the difficulties arising from increasing display gain around the target. An examination of the relevant characteristics of motion suggested that a reformulation of Keele's discrete submovement model of discrete movement could best explain these data.