Analysis Of Controllability And Stability On Computer Pointing Devices

The development of GUI makes wide use of computer pointing devices. The most common pointing device is mouse, its amounts of use can lead to varieties of problems in musculoskeletal fatigue and uncomfortableness, so it is required to search an excellent type of alternative device. The most popular alternative device at present is trackball, but the study about which is scarce. It is necessary to study the operating traits of different pointing devices and design optimal device, which can make users have more efficient and less harmful and unhealthful operation. Controllability and stability are important index of evaluating pointing device in view of human factor. Our research used tracking task needed continuous and accurate control, and studied the operating controllability and stability of three pointing devices: mouse, the index finger operating and thumb operating trackballs. Based on the results, the operating traits of the three devices were compared in detail.Two experiments were conducted in this study. The two experiments tested the effect of target path and moving speed to the operating controllability and stability of mouse, the index finger operating and thumb operating trackballs. In addition, subjects were required to have a subject evaluation to the operating controllability and stability of three pointing devices, and the relation of objective and subjective controllability and the relation of operating controllability, stability and fatigue degree were analyzed .Main findings of this research are as following:1. Target path has a more effect on the operating controllability and fatigue degree of mouse, and the index finger operating and thumb operating trackballs, but only has a less effect on the operating stability of the three pointing devices.2. Target speed has an effect on the operating controllability, stability and fatigue degree of mouse, and the index finger operating and thumb operating trackballs.3. In general speaking, mouse is better than the two trackballs and the two trackballs only have slight difference in the operating controllability and stability, but mouse is slightly higher than the two trackballs in subject operating fatigue degree.4. This research find; the relation among subjective operating controllability and fatigue degrees and objective operating controllability and stability is complicated, objective operating controllability and stability probably reflect operating performance, but subjective operating controllability and fatigue degrees probably reflect force degree and work load, which show that many index should be used to evaluate operating activity of pointing device.5. Another finding of this research is that there is a trade-off property between operating performance and work load in operating pointing device, that is, operating controllability(objective and subjective),stability and work load of pointing devices decline when target speed increase, under middle operating speed, operating controllability, stability and work load of pointing devices is relatively better.