Mok’s Principles for Metaphors
Predictability From the user's point of view, does the program interface behave in a predictable manner that is in agreement with what the designer planned?
Consistency Does the program interface respond consistently to a user's behavior, giving the same results for the same input each time?
Progression Does the program interface advance at an appropriate pace from simplicity to complexity, never requiring more complexity than necessary or than the user is ready to handle?
Theoretical Foundations of Multimedia Chapter 7