A Breakdown of the Psychomotor Components of Input Device Usage
http://www.surl.org/usabilitynews/71/input_devices.html

Slocum, Jeremy
Usability News
2005

Abstract:

This study investigates the breakdown of the psychomotor components of three different input devices, the mouse, trackball, and RollerMouse™ using the Stochastic Optimized Submovement Model. Primary movement time (PMT), Total Movement Time (TMT), Primary Movement Distance (PMD), and Total Movement Distance (TMD) were examined for each device. Results showed that psychomotor variables related to the primary phase of movement help to pinpoint how performance efficiency is affected by a particular device. For example, the relationship between %PMD and efficiency suggests that a device that affords users an initial accurate movement decreases the need for more or longer corrective submovements, thus reducing movement time.