Saturday, December 26, 2009

Fitts' Law, a small presentation

One of the most known and applied laws of Human-Computer Interaction is the Fitts' law. A good interface should optimize and reduce the time presented by this formula :

"a" and "b" are only two constants, defined by the used hardware properties like a mouse. D is the distance from the object and W is the object width.
I want only to say that this is only the first formula, many other derviate ones exist.

The most important is how to design interfaces to optimize the time to select an object. I want to present the openSUSE menu where the developers have applied this :


When I've clicked in Developpement option, all the menu has changed.
Being different from a "standard" menu, the user haven't to move his mouse by width, but only up and down and no new menu windows are created. So less mouse movement.

In this precise example, not only the Fitts' law is applied, but also the Steering Law (Accot-Zhai).

This is just an introduction, and presentation for a small example, but I will to show interface features in other projects.