In design it is important to shoe the effect of an action. ... Feedback is critical.

It was always amusing to be inside Apple and read what journalists said we were doing

The designer has an obligation to provide an appropriate conceptual model for the way that the device works. It doesn't have to completely accurate but it has to be sufficiently accurate that it will help in both the learning of the operation and also dealing with novel situations.

In design it is important to shoe the effect of an action. ... Feedback is critical.

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.

Any time you see signs or labels added to a device, it is an indication of bad design: a simple lock should not require instructions.

Forget the complaints against complexity; instead, complain about confusion.