By adding one button, we introduced a new functional area and let the user switch back and forth with ease. We evaluated these designs with scenarios derived from the contextual inquiry and with informal usability testing at our site and the users' workplace. Using an early prototype, designers who had never seen the interface painted models with only a cursory introduction and even competed for the best 3D painting at a national design conference. The integration of 3D turned out to be so natural to many traditional designers that they did not realize they were using a 3D product. By grounding our design in the user's work practice, our early findings have shown that we were able to successfully match to the user's model.
Users can focus on their jobs instead of the mechanics and artifacts of technology.
We will be conducting more rigorous usability studies in design studios to test these findings. Addison-Wesley, New York 1990. The Psychology of Everyday Things. Basic Books, New York 1988.