Good Article on User Interface Design Rules

I found a well-written article about user interface design rules. "Understanding user interface design rules," by Jeff Johnson, EE Times. (Two part article links:  Part 1  | Part 2 )

The take-aways are:

• Make the operation task-focused, simple, and consistent. Bring the operation itself as close to possible as what the user wants to accomplish (the outcome), not what the device knows how to do (the mechanisms available).
• Keep things simplicity and consistent.
• Make the terminology familiar (and task-focused, and simple). Use the meaning that people expect to see, not jargon. Use different terms whenever there is a concept that differs in an important way. Don't use different terms if the difference doesn't matter to the user.
• Make mistakes low cost (e.g., provide undo) so people aren't afraid to explore the interface.

The concept of an objects/actions matrix looks interesting. The idea is you put objects as the rows of a matrix and actions on those objects as a column.  Whenever an action is permissible for an object it gets a check mark in the matrix.  Good designs have square, densely filled in matrices (simple, consistent). Bad designs have large, sparsely filled in matrices (complex, inconsistent).

This article is well worth the time for anyone who designs embedded systems.