Human Performance Model for Combined Steering-Targeting Tasks

The combined steering-targeting tasks are frequently encountered within the window-type environment. For example, within a menu driven interface, the user is required to steer down a menu and then to click on a target. In this paper, human performance for these tasks was measured and a mathematical model was proposed to describe the human performance. The cursor movement in the combined steering-targeting tasks had a positive acceleration form at the starting period until about 10mm and a uniform velocity was maintained during the intermediate period and a negative acceleration was observed at the ending period. The proposed model consisted of two terms in which the first being the classical Fitts' term and the second being the steering law suggested by Drury. This model provided a good fit to the data obtained from the experiments (r2 = 0.936) as well as the data obtained by Kvalseth (r2 = 0.982).