[from John Hanacek's "As We May Sketch"]
In Don Norman’s “The Design of Everyday Things” he provides ‘principles of good design,’ which are:
* Visibility. By looking, the user can tell the state of the device and the alternatives for action.
* A good conceptual model. The designer provides a good conceptual model for the user, with consistency in the presentation of operations and results and a coherent, consistent system image.
* Good mappings. It is possible to determine the relationships between actions and results, between controls and their effects, and between the system state and what is visible.
* Feedback. The user receives full and continuous feedback about the results of actions.