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.
Donald A. NormanI believe that the Apple Shuffle is an excellent compromise among the conflicting requirements of simplicity, elegance, size, battery life, and function
Donald A. NormanThe problem with emotion was that it was clearly something important, but-at least according to the old philosophy-it was something to overcome.
Donald A. NormanUser experience is really the whole totality. Opening the package good example. It's the total experience that matters. And that starts from when you first hear about a product experience is more based upon memory than reality. If your memory of the product is wonderful, you will excuse all sorts of incidental things.
Donald A. Norman