Humane Interface, The: New Directions for Designing Interactive Systems

5-2. Elementary Actions Cataloged

As you design an interface, you should have the palette of possibilities arrayed in your mind, much as a painter has his colors organized. The spectrum of elementary actions that a user can perform is remarkably limited. From this set of elementary actions, all user interaction is built. With a keyboard, you can tap keys or press and hold them while you perform other actions. With a GID, you can move a cursor within the bounds of the display (or displays) on your system, and you can signal the computer, using the speed, direction, and acceleration of the GID, although you usually use GID speed and acceleration only as an aid to pointing. With a GID button, you can signal display locations to which you are pointing ...