One way to manage interaction design complexity is to have commands serve double duty . There are two ways of doing this, with different usability implications:
- Generic commands use the same command in different contexts to achieve conceptually the same outcome , even though details of the specific effects might differ.
- Overloaded commands use variants of the same command to achieve different outcomes — sometimes depending on the context and other times depending on where the command appears on the screen.
I discussed generic commands in depth in an earlier article. The most famous generic command these days is the pinch-zoom gesture , which works in most touchscreen user interfaces. In...