Movement variability and speed of performance using a head-operated device and expanded membrane cursor keys

Abstract

The performance of computer pointing devices is traditionally measured in terms of speed and accuracy. Such measures are important when comparing input devices for specific users. Although speed and accuracy data verify that performance differences exist, researchers are frequently left to speculate as to the cause. This study explores the value of including data on movement variability in investigations comparing performance of computer input devices for persons with disabilities. Movement variability represents the degree to which recorded sample points vary from the straight-line path between a home location and a target. Analysis of movement variability data provides rehabilitation specialists with clinically valuable information beyond what can be ascertained from measures of speed and accuracy alone. © Springer-Verlag 2004.