April 2016
Intermediate to advanced
325 pages
9h 24m
English
Our product actually reflects three different models:
How the user thinks the product works. This is the user’s mental model of the product.
How the product is presented to the user in the user interface. I call this the UI model.[42]
How the product is implemented. I call this the implementation model.[43]
In an ideal product, these three models are consistent with each other. The user interface perfectly represents the implementation, and the user perfectly understands what he sees.