What makes something simple or complex? It's not the number of dials or controls or how many features it has: It is whether the person using the device has a good conceptual model of how it operates.

The designer shouldn't think of a simple dichotomy between errors and correct behavior; rather, the entire interaction should be treated as a cooperative endeavor between person and machine, one in which misconceptions can arise on either side.

Having the best product means nothing if the people won't buy it.

When you have trouble with things—whether it's figuring out whether to push or pull a door or the arbitrary vagaries of the modern computer and electronics industries—it's not your fault. Don't blame yourself: blame the designer.

I believe that robots should only have faces if they truly need them

Attractive things work better.

Complexity is acceptable as long as it is intelligible and necessary. We want to avoid needless complications.