Improvement of the Model of Fitts' Law in a Two-Dimensional Pointing Task
Hirokazu Iwase, Atsuo Murata, Masatoshi Kitaoka, Juvy Balingit · Transactions of the Society of Instrument and Control Engineers · 2004
Fitts' law is a useful means to accurately model human movement time, and has been widely adopted in human factors and human-computer interaction. As Fitts' performance model is one-dimensional, it may not be proper as a performance predictor in a two-dimensional pointing task. The purpose of this study is to suggest new definitions of target size and target distance in the performance model which predicts the pointing time of two-dimensional pointing task in computing systems. Target was a rectangle. Experimental factors were target size, aspect ratio of target, target distance, and approach direction to the target. Pointing time, coordinate of pointer (mouse pointer), and trajectory length were measured. Two-dimensional effective target width was used in the five definition of target size (W', min(W, H), W+H, √W·H, W·H; W is target width, H is target height). Direct distance and trajectory length were adopted as target distance. From the result of contribution of performance model, it was clarified that applying W' as target size and trajectory length as target distance was more effective than a traditional method.