Measuring the difficulty of steering through corners

Abstract

The steering law is intended to predict the performance of cursor manipulations in user interfaces, but the law has been verified for only a few path shapes and should be verified for more if it is to be generalized. This study extends the steering law to paths with corners. Two experiments compare the movement times of negotiating paths with corners to straight paths with the same width and movement amplitude. The experimental results show a significant effect on the movement times due to the corners, extending far into the legs of the path's corner. Modeling the results using resource theory, a cognitive theory for divided attention, suggests that steering through corners is two simultaneous tasks: steering along the legs of the corner and aiming at the corner.