Apple General Design Principles

1. Metaphors from the real world
• Use concrete metaphors and make them plain, so that users have a set of expectations to apply to computer environments.
• Whenever appropriate, use audio and visual effects that support the metaphor.
2. Direct manipulation
• Users want to feel that they are in charge of the computer's activities.
3. See-and-point
(instead of remember-and-type)
• Users select actions from alternatives presented on the screen.
• The general form of user actions is noun-then-verb, or "Hey, you --- do this."
• Users rely on recognition, not recall; they shouldn't have to remember anything the computer already knows.
• Most programmers have no trouble working with a command-line interface that requires memorization and Boolean logic. The average user is not a programmer.
4. Consistency
• Effective applications are both consistent within themsolves and consistent within one another.
5. WYSIWYG
(What you see is what you get)
• There should be no secrets from the user, no abstract commands that only promise future results.
• There should be no significant difference between what the user sees on the screen and what eventually gets printed.
6. User control
• The user, not the computer, initiates and controls all actions.
7. Feedback and dialog
• Keep the user informed.
• Provide immediate feedback.
• User activities should be simple at any moment, though they may be complex taken together.
8. Forgiveness
• Users make mistakes; forgive them.
• The user's actions are generally reversible; let users know about any that aren't.
9. Perceived stability
• Users feel comfortable in a computer environment that remains understandable and familiar rather than changing randomly.
10. Aesthetic integrity
• Visually confusing or unattractive displays detract from the effectiveness of human-computer interaction.
• Different "things" look different on the screen.
• Users should be able to control the superficial appearance of their computer workplaces -- to display their own style and individuality
• Messes are acceptable only if users make them -- applications aren't allowed this freedom.