The Apple Human Interface Guidelines

1.      Simple design is good.

2.      People deserve and appreciate attractive surroundings. A mess is acceptable only if the user makes the mess.

3.      Good design must communicate not just dazzle.

4.      Objects should look like what they do so that the user can recognize them and point to them.

5.      Consistency should be valued over idiosyncratic cleverness.

6.      The transfer of skills is one of the most important benefits of a consistent interface.

7.      The environment should appear to remain stable, understandable, and familiar.

8.      There should be little to no difference between what the user sees and what the user gets.

9.      The user not the computer should control the action.

10.  The interface should stimulate the feeling that the user is in charge of the system, and it should be fun to use.

11.  The user should be kept informed of what’s going on via messages (presented in dialog boxes).

12.  The user should be allowed to do anything reasonable and be forgiven if a mistake a made.

13.  Generally the interface should use metaphors.

14.  These metaphors should be supported with audio and visual effects.

15.  Animation, when used sparingly, is one of the best ways to draw a user’s attention to a place on the screen.

16.  There should always be a way out.