Distribution of movement time in a target-aiming task.
Various characteristics of the distribution of movement time were analyzed for a task involving serial and rotary arm movements aimed at a target. For experimental data generated from five Ss, (a) the distribution tended to be unimodal and more peaked than a normal distribution, (b) the skewness of the distribution was predominantly positive and (c) the standard deviation, in addition to the mean, of movement time was significantly affected by the complexity of the task as measured by Fitts' index of difficulty, while the skewness and the kurtosis were not. For the average results for the Ss, a first-order linear model with the standard deviation of movement time as the dependent variable and Fitts' index as the independent one explained 67% of the variation in standard deviation as compared to 98% of the variation in mean movement time accounted for by the Fitts' index.
D000328:Adult; D001076:Aptitude; D001132:Arm / Q000502:physiology; D006801:Humans; D008297:Male; D008433:Mathematics; D009048:Motor Skills; D013647:Task Performance and Analysis; D013997:Time Factors; D014796:Visual Perception