Anarchaia found and linked to my page with Jef Raskin’s design rules. I’ll have to check the other cool stuff collected by Christian Neukirchen.
Summary of design rules by Jef Raskin
In 2002 Jef Raskin wrote to Tom Gilb "A nearly one page summary of design rules".
The first principle. When using a product to help you do a task, the product should only help and never distract you from the task.
The second principle: An interface should be reliable.
The third princple: An interface should be efficient and as simple as possible.
The fourth principle: The suitability of an interface can only be determined by testing.
The fifth principle: An interface should be pleasant in tone and visually attractive.
Then Jef Raskin concludes:
An interface should be effective, habituating, reliable, efficient, and tested. To the extend that doing so does not conflict with these essentials, an interface should also be attractive.
[read Jef’s nearly one page summary of Raskin’s design rules]