Top Highlights

• Almost anything that creates unnecessary problems, my correspondents report, is a “Norman thing”:
• one of the most important principles of design: visibility. The correct parts must be visible, and they must convey the correct message.
• Just the right things have to be visible: to indicate what parts operate and how, to indicate how the user is to interact with the device. Visibility indicates the mapping between intended actions and actual operations.
• affordance refers to the perceived and actual properties of the thing, primarily those fundamental properties that determine just how the thing could possibly be used
• the fundamental principles of designing for people: (1) provide a good conceptual model and (2) make things visible.