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

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.

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.

Design is really an act of communication, which means having a deep understanding of the person with whom the designer is communicating.

Knowing how people will use something is essential

To me, error analysis is the sweet spot for improvement.

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