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.

It is not enough that we build products that function, that are understandable and usable, we also need to build products that bring joy and excitement, pleasure and fun, and, yes, beauty to people's lives.

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.

We expert teachers know that motivation and emotional impact are what matter.

Readers always seem to think that the author has some control over the design of their books.

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.

Behavioral design is all about feeling in control. Includes: usability, understanding, but also the feel.