The man who built a better mouse trap

An explanation for the phenomenon can be had through Fitts' Law, which states that the time to home in on a target is a function of the distance to, and size of, the target. Personally, I think the answer is more Neolithic: we Homo sapiens have been throwing rocks a lot longer than we've been playing computer games, so the sweeping motion is natural.

Because of this biological magic, the mouse still functions pretty much the way it always has -- unlike microprocessors or graphics chips. Two of the biggest changes have been that the cord was moved from the back of the mouse to the front, and the main control button has shifted from the right side to the left.

Interestingly enough, the fact that mice are associated with simplicity is a disappointment to Engelbart. He believes that better, more-elaborate input-output devices could increase collaboration and cooperation. Over the years, he has developed control devices for both hands -- a mouse for one hand and a five-key keyboard for the other -- a setup that can increase the speed of performing certain tasks, suggest experimental results.

The primary knock against these devices is that they require training. But how many of us stopped at the tricycle as kids? As Engelbart noted, we all managed to move up to the more-complex two-wheeler.