So what does a good teacher do? Create tension - but just the right amount.

A big ethical question is what happens after people stop using the device. Does it degrade the environment? Could it have been designed so it would actually be good for the environment?

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

The argument is not between adding features and simplicity, between adding capability and usability. The real issue is about design: designing things that have the power required for the job while maintaining understandabili ty, the feeling of control, and the pleasure of accomplishment.

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.

The world is complex, and so too must be the activities that we perform. But that doesn't mean that we must live in continual frustration. No. The whole point of human-centered design is to tame complexity, to turn what would appear to be a complicated tool into one that fits the task, that is understandable, usable, enjoyable.

The current paradigm is so thoroughly established that the only way to change is to start over again.