1. © 2000 Franz Kurfess Cognitive Models 1

2. © 2000 Franz Kurfess Cognitive Models 2 Norman’s Cognitive Model [ Seffah ]

3. © 2000 Franz Kurfess Cognitive Models 3 Cognitive Design Principles  Bridging the Gulf of Evaluation  feedback about the system status  utilize knowledge the user has already  provide explanations, mental model  Bridging the Gulf of Execution  exploit affordances and automatic cognitive processes  don’t astonish the users!  use icons and widgets, but keep them consistent and make them easy to use

4. © 2000 Franz Kurfess Cognitive Models 4 Aspects of Design Principles  Affordances  Causality  Visible Constraints  Mapping  Transfer Effects  Population Stereotypes  Conceptual Models

5. © 2000 Franz Kurfess Cognitive Models 5 Mapping: Stove Controls Arbitrary - 24 possibilities - Requires visible labels and memory (e.g. back/right, front/left, back/left, front/right Paired - 2 possibilities per side = 4 possibilities - Requires label (e.g. back, front) Full Mapping - 4 possibilities - Requires no visible labels and memory [ Seffah ]

6. © 2000 Franz Kurfess Cognitive Models 6 Mapping and Causality  good example: Netscape preferences  not so good: Clip Art Gallery [ Seffah ]

7. © 2000 Franz Kurfess Cognitive Models 7 Transfer Effects [ Seffah ]

8. © 2000 Franz Kurfess Cognitive Models 8 Good Conceptual Model  affordances  holes for fingers  constraints  big hole: several fingers  small hole: thumb  transfer  learned when young  applies to all kinds of scissors [ Seffah ]

9. © 2000 Franz Kurfess Cognitive Models 9 Bad Conceptual Model  affordances  four buttons, functions unclear  constraints and mappings  unclear, no visible relations between objects and effects  transfer  must be learned explicitly  different for different models  conceptual model is not intuitive [ Seffah ]