Principles of interaction design

Interaction design is one of the primary duties of any elearning designer. The design of interactivity is often shared by the instructional designer, who thinks up and describes interaction types, and the visual designer who brings them to life and adds to them. Either way, good interaction design is essential to good elearning, and is inextricably linked to the interface and multimedia design.

Bruce Tognazzini (otherwise known as TOG) of the world renowned Nielsen Norman Group has published a set of fundamental principles of interaction design. All of these are applicable to elearning, all the more so if you're creating applications or self-contained tutorials. The 16 fundamental principles are:

1. Anticipation
2. Autonomy
3. Color blindness
4. Consistency
5. Defaults
6. Efficiency of the user
7. Explorable interfaces
8. Fitt's Law
9. Human interface objects
10. Latency reduction
11. Learnability
12. Metaphors
13. Protect user's work
14. Readability
15. Track state
16. Visible navigation
    

Don't sit there trying to decode the list -- take a look at the complete explanation here:
http://www.asktog.com/basics/firstPrinciples.html