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.

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

No product is an island. A product is more than the product. It is a cohesive, integrated set of experiences. Think through all of the stages of a product or service - from initial intentions through final reflections, from first usage to help, service, and maintenance. Make them all work together seamlessly. That's systems thinking.

The hardest part of design ... is keeping features out.

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

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

We delude ourselves if we believe that skilled behavior is easy, that it can come about without effort. We forget the years of tuning, of learning and practice it takes to be skilled at even the most fundamental of human activities: eating, walking, talking, reading, and writing. It is tempting to want instant gratification - immediate expert performance and experiential pleasure - but the truth is that this primarily occurs only after considerable amounts of accretion and tuning.