Retrievability, Learning, Efficieny of use, ease of use at first encounter, Aesthetics
Either can be representated graphically or textually
e.g on a map.The museum is located here: DecalrativeTo get there you need to take a right..go up 3 blocks, next left then its on the corner: Procedural
Imageability supports remembering and reasoning
Pin number
Procedural
Unconcious
typing, driving etc
Means-end reasoning
Processes, procedures
Declarative
Know that: concepts, relationships, things & actions
Examples
Tap
users model: water coming out, temperature, pressure
Designers model has 2 seperate water supplies mixed
