What users believe they know about a UI strongly impacts how they use it. Mismatched mental models are common, especially with designs that try something new.
Mental models are one of the most important concepts in human–computer interaction (HCI). Indeed, we spend a good deal of time covering their design implications in our full-day seminar on Principles of Interface Design.
Here, I'll report a few examples from our usability studies. Not coincidentally, using concrete examples often helps people understand abstract concepts (such as mental models).
First, though, you have to suffer one bit of theory — namely the definition of mental models. A mental model is what the user believes about the system at hand.



