Visual Distinctness What is easy to find How to represent quantitity

1. Visual Distinctness What is easy to find How to represent quantitity • Lessons from low-level vision • Applications in Highlighting • Icon (symbol) design - Nominal • Glyph design – representing quantity

2. Spotfire product

3. Visual symbols

4. Architecture for visual thinking

5. Primitives of Perception (the graphemes). • The whole visual field is processed in parallel • This machinery tells us what kinds of information are easily distinguished • Popout effects (general attention) • Segmentation effects (dividing up the visual field)

7. Channel theory

8. Segmentation by Primitive Features

9. Orientation and Size(Gabor primitives)

10. Image segmentation based on texture

11. Texturesfor Maps

12. What is easy to find? • A priori salience • Top down salience • Knowledge

13. Pre-Attentive Processing

14. Color is Pre-Attentive (Pops out)

15. Generic Pre-Attentive Experiment • Number of irrelevant items varies • Pre-attentive 10 msec per item or better. Triesman, A., and Gormican, S. Feature analysis in early vision: Evidence from search asymmetries. Psychological Review, 95(1) 15-48.

16. Color

18. Orientation

20. Motion

22. Size

24. Simple shading

26. Conjunction (does not pop out)

27. Semantic Depth of Field

29. Compound features (do not pop out)

31. Surrounded colors do not pop out

34. Laws of pre attentive display • Must stand out on some simple dimension • color, • simple shape = orientation, size • motion, • depth • Lessons for highlighting – one of each

35. Asymmetries

36. Lessons: Highlighting how to make information available to attention Using color Using underlining A flying box leads attention Blinking momentarily attracts attention Blinking momentarily attracts attention Motion elicits an orienting response

37. More on Conjunction (no pop)

38. Redundant coding

39. Pre-attentive conjunction

40. Conjunctions of motion and shape do pop out. (color also?) • McLeod, P., Driver, J. and Crisp, J. (1988) Visual search for a conjunction of movement and form is parallel. Nature 332, 154-155. • Driver, J., MacLeod, P. and Dienes, Z. (1992) Motion coherence and conjunction search: Implications for guided search theory. Perception and Psychophysics. 51, 1, 79-85.

42. MEGraph: Experimental system • Allows for various topological range highlighting methods MEGraph Goal from 30 to 2000 nodes

43. Pre-Attentive Channels • Form (orientation/size) • Color • Simple motion/blinking • Addition/numerosity (up to 3) • Spatial, stereo depth, shading, position

44. Pre-Attentive Conjunctions • Stereo and color • Color and motion • Color and position • Shape and position • In general: spatial location and some aspect of form

45. Pre-Attentive Lessons • Rapid visual search (10 msec/item) • Easy to attend to • Makes symbols distinct • Based on simple visual attributes • Faces, etc are not pre-attentive

46. Designing symbols

47. Perceptual Channels • Color (3) • Shape (size, orient) • Motion (2?) • Texture (2++) • Position (x,y)

48. Spatial Channels Like interferes with like

49. Distortions: Size contrast effect

50. Orient contrast