What kind of pointing device is most efficient?
|This is an actual
research question in the field of Human Factors Analysis.
The Fitts Law program provides the means to do the appropriate experiment. It works like this:
Mouse click on the green stripe and it turns red. Click back and forth as fast as possible. Stripes get fat or thin, near or far.
These graphs show that the IBM pointing stick is less efficient than a mouse. The program provides the means to analyze thedata and make graphs within a spreadsheet.
This project asks how the speed and accuracy of our motor movements (fingers, hands,
feet, etc.) depends on the magnitude and precision required by the task. It turns out that
there is a general psychological law that describes this ability and that this law is
applicable to movements as small as those made when using a microscope manipulator and as
large as those made when using the entire body. The law was discovered by a University of
Michigan psychologist named Paul Fitts.
The project is also interesting because it may clarify some questions that you may have had about how the computer mouse works--what is the best way for the human to control the movement of the screen cursor. (And, what are the best ways for the computer to process the movements of the mouse for cursor movement?) Similar questions come up in the design of controls for high performance aircraft and in other critical applications.
Dr. Stuart Card did the studies for the Xerox Corporation that showed that the mouse was a viable way for people to input information into the computer (Card, English, and Burr,1978). Recently, he said that what convinced the Xerox management to introduce the mouse commercially was the use of Fitts Law, to explain why human performance with the mouse was the way it was. The slope of the Fitts Law function with the mouse was about the same as that of the unaided hand. This showed that the limitations of the mouse were not in the mouse itself, but in the humans eye-hand mechanism. "And that meant," Card said, "if you put out the device on the market, somebody was not going to come along and just do a better device six months later and knock you out of the market. It meant that the mouse would have staying power" (Hann, 1997).