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.

Will robot teachers replace human teachers? No, but they can complement them. Moreover, the could be sufficient in situations where there is no alternative––to enable learning while traveling, or while in remote locations, or when one wishes to study a topic for which there is not easy access to teachers. Robot teachers will help make lifelong learning a practicality. They can make it possible to learn no matter where one is in the world, no matter the time of day. Learning should take place when it is needed, when the learner is interested, not according to some arbitrary, fixed schedule

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

Good design is also an act of communication between the designer and the user, except that all the communication has to come about by the appearance of the device itself. The device must explain itself.

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

Simplicity design axiom: The complexity of the information appliance is that of the task, not the tool. The technology is invisible.

Isn't one of your first exercises in learning how to communicate to write a description of how to tie your shoelaces? The point being that it's basically impossible to use text to show that