- Mental model theory suggests that the mind constructs "small-scale models" of reality to understand situations. Mental models can be based on perception, imagination, or comprehending language. They resemble pictures and can represent tangible or abstract concepts. - Mental models have a structure analogous to what they represent. Critics argue the mind uses inference rules rather than models for deductive reasoning. The concept of mental models was applied to human-computer interaction in the 1980s. - Mental models are internal representations of systems and environments derived from experiences. Accurate mental models correspond to real outcomes. Models can represent how systems work or how people interact with systems.

1. Mental Models Joel Kline Texas Tech University May 23, 2007

2. If I give you my keys…could you drive my van?

3. Mental Model Theory Originates from Scottish Psychologist Kenneth Craik’s work that suggests the mind constructs "small-scale models" of reality (1943). Mental models can be constructed from perception, imagination, or the comprehension of discourse. They normally underlie visual images, but can also be abstract and represent situations that cannot be visualized. Mental models have structure that is analogous to the structure of what they represent. Resemble the “picture” theory of language described by Ludwig Wittgenstein in 1922. Critics of the theory argue that the mind uses inference rules not models as the basis for deductive reasoning. Donald Norman and Richard Young (independently) were the first to devise a terminology for Mental Models for use in HCI around 1983

4. Definition Representations of systems and environments derived from experience. A mental model is accurate when the real and imagined outcomes correspond Two Categories Models of how systems work Models of how people interact with systems

5. Good Design Occurs… Results when designers have an accurate view of the system (easy) and an accurate view of the user’s interaction with the system (hard). The designer then designs a system interface that merges both models.

6. Designers can learn the user: Through personal use of the system Laboratory testing (usability, focus groups) Direct Observation of users

7. Where do we “get” models? External interface conventions - come to your interface with the users Internal interface conventions - build or break trust

8. For both interface users and media developers Print model has 600 years behind it Build trust with consistency Consistency can evolve Consistency is Contextual

9. MM Examples Automobile Doors with knobs that don’t turn Any computer interface device. Have you ever tried a Dvorak keyboard?

10. InDesign Examples Folios Right to left reading Consistent Hierarchy Consistent use of bold, italics, and underline Typically an issue with longer documents

11. InDesign Interface MM

12. When you have no MM?