A fundamental study on pointing force applied to the mouse in relation to approaching angles and the index of difficulty

The objective of this study was to obtain empirical data for pointing force applied to the mouse in relation to the characteristics of a display layout such as target areas and approaching angles to the target areas. For our experiment, a 5 mm-diameter force sensitive resistor was equipped at the top of the microswitch inside the mouse for the measurement of the pointing force. A total of five subjects were instructed to perform a series of pointing tasks as quickly and precisely as possible with different target size and approaching angles. The ANOVA showed a significant main effect for target size on the pointing force and the movement time. Indices of difficulty (IDs) were calculated by target sizes and linear distances between targets. The smallest pointing force was found in the conditions with highest IDs. Detailed analyses on mouse use with this methodology can contribute much to the ergonomic design of graphical user interface (GUI) that enables more comfortable use of the mouse as well as the evaluation of computer tasks with the risk of musculoskeletal disorders. This research provides a practical technique for measuring pointing force applied to the mouse, which would be valuable for evaluating VDT tasks in epidemiological studies. Software designers, especially who engage in GUI, may use information associated with the relationship between operating force and characteristics of display layouts.