1. Visual Thinking--Review Michael Mills Stanford Center for Innovation in Learning April 3, 2003

2. Goals of the talk 1. Review Rudolf Arnheim’s Visual Thinking 2. Functions of Visualization

3. Visual thinking--Arnheim What is the relationship between seeing and reasoning? Is seeing itself a kind of problem-solving? Are there close ties between art and science? Between sensory experience and abstract thought? Does productive thought take place in the realm of imagery? How can images support thinking and learning? -Precursor of Information Visualization -Design Principles of for Informative Displays -

4. Gestalt approach to perception Gestalt means pattern--whole more than sum of parts Mind is NOT a Tabula Rasa formed by associations Wertheimer, Kohler, Arnheim Mind imposes patterns on the visual field Operates by organization principles - “force fields” and dynamics Aesthetics implicit in perceptual organization

5. What do you see?

7. Brain organizes visual field according to simplest possible organization Gestalt laws win over experience and learning--Camouflage

8. What shape do you see?

11. Stroboscopic Motion (Phi) See motion streak although not occurring in the visual field. Proof that brain imposes organization. -“short circuit” in neurons

12. similarity proximity brightness speed size orientation continuity common fate Gestalt Grouping “Laws”

13. Structure from Motion

14. Gestalt Grouping “Laws”

15. Perception as Problem-Solving Simplicity Rule: Brain chooses simplest ‘theory’ to fit the data.

16. Perception and behavior as a “composition” of ideals --Bregman

18. Closure

19. Figure and Ground

20. Importance of Context

21. Emmert’s Law Perceived size is a function of perceived distance

22. Pictures, Symbols and Signs Images Abstract forces Practical Things Images can be used to picture the way things appear in the real world… …or symbolically to give visible shape to patterns of forces Images regard the world in two opposite directions

23. 3 Functions of Images Not kinds of images, but FUNCTIONS they serve. What is the communicative intent? Picture, Symbol and Sign SIGN of Danger SYMBOL of Hierarchy PICTURE of a mountain

24. SIGNS Image used as a sign when it stands for specific content without trying to portray its appearance Relation between image and referent is associative, arbitrary Effective signs evoke underlying structural qualities and forces “Danger”

25. SIGNS Maluma or Takete?

26. PICTURES Images used as a picture when used to portray things at a lower level of abstraction than itself Picture grasps relevant aspects of natural features of objects in the real world A picture is not merely a replica -editing, selection “Mountain”

27. PICTURES Picture can exist at different levels of abstractness Involves selection and interpretation -- not just realistic portrayal Not just asking perceiver to “fill in” Pictorial interpretation concerned with generic qualities Formal, structural qualities reinforce abstract forces

28. PICTURES Icon design highlights the generic qualities.

29. SYMBOLS “Hierarchy” Referent is at a higher level of abstraction than the image itself Gives visible shape to abstract forces, ideas…

30. SYMBOLS Referent is at a higher level of abstraction than the image itself Gives visible shape to abstract forces, ideas…

32. Two scales of abstraction

33. LOW HIGH Rich sensory record Foregrounding relevant features Describing, indexing, coding Discovering formal Relations Formalisms Powerful tool for analysis and visualization of human activity in real-world places Visualization in DIVER

34. Cartoons and Caricatures Mix symbolic and pictorial function

35. Tide Table for Navigation