Effects of angle of approach on cursor movement with a mouse: Consideration of Fitt's law

Research related to various aspects of human-computer interactions has become increasingly important to the design and implementation of effective interface systems and input devices. As the man-machine interface has become more direct, the analysis and application of models to account for this interaction have received increasing attention by investigators. In that regard, the speed and accuracy of human motor movements associated with computer input devices have often been modeled by Fitts' law. Most such analyses, however, have not considered the angle of approach as a factor. The present study investigated the interactive effects on movement time of the angle of approach, the size of the target, and the distance to the target for the use of a mouse to select icon-like targets presented on a computer's display screen. Angle of approach, target size, and target distance significantly affected movement time. Although the global R2 based on a Fitts' law linear model was low in comparison with other studies, an analysis of the residuals showed that the linear model's effectiveness in prediction interacted with the other variables under investigation.