Visualization in science

1. 30th International Conference on INFORMATION TECHNOLOGY INTERFACES Cavtat, Croatia, June 23-26, 2008 Visualization in science Nataša Tepić

2. dictionary: Visualisation is a relatively new term which describes the process of representing information or ideas by diagrams or graphs. expansion: maps, plots, animations, video, movies, ... What isvisualization?

3. You must never tell a thing. You must illustrate it. We learn through the eye and not the noggin.Will Rogers (1879 - 1935)

4. One picture is worth ten thousand words. Frederick R. Barnard: Printer's Ink 10.03.1927.

5. JMP The greatest value of a picture is when it forces us to notice what we never expectedto see. John Tukey

7. History • till 16thcentury data visualization = maps

8. the oldest known map (town map)6200 BCMuseum at Konya, Turkey

9. the first world map- Anaximander from Miletus in Asia Minor (610-546 BC), Turkey(his map has been lost, Herodotus describes it in books“The Histories” II & IV)

10. History • in 15th century - Nikolaus Krebs (Nicholas of Cusa, Nicolaus Cusanus)developed graphs of distance vs. speed, presumably of the theoretical relation • during 16th century - development of geometric diagrams and various maps for data exploration– official start of data visualization • during 17th century - analytic geometry (René Descartes, Pierre de Fermat, ...) , theories of errors of measurement and estimation, the birth of probability theory, and the beginnings of demographic statistics and '' political arithmetic''

11. What do we see? • form • color • depth • motion

12. Human visual system • human sight reacts more intensively on contrast than on intensity • colors which we *see* are not completely identical to the colors in the nature • purpose of human sight is constantobject recognition regardless of angles, distance or lighting

14. Seeing is a Complex Process • Our brain constructsimage from: • information from our eyes • information stored in our brain

15. perception • process of collecting information about worldthrough our senses and their interpreting • perception depends on cultural heritage • perception changes with experience

16. Do you ever get something like this via e-mail?

22. Optical illusions • Illusions trick us into perceiving something differently than it actually exists, so what we see does not correspond to physical reality. The word illusion comes from the Latin verb illudere meaning, "to mock."

23. Why areoptical illusionsimportant fordata visualization? • inappropriate visual stimulation can confuse our brain • manipulativevisual stimulation can cause wrong interpretation

24. Optical illusions • Problems with visual perception: • area • angles • perspective

25. 10 ?? How much is the area of circle B? A B • answer: 17

26. angle problem

28. perspective problem

29. co-effects

30. Müller-Lyer

31. co-effects

32. co-effects

33. co-effects (pattern completion)

34. Johann Poggendorff’s illusion

35. co-effects

36. co-effects

38. co-effects

39. co-effects

40. Color Meaning Colors are non-verbal communication. They have symbolism and color meanings that go beyond ink. redaction, confidence, courage, vitality blueunity, harmony, calmness, coolness, conservatism yellowjoy, optimism, summer, cowardice, greed greenspring, fertility, youth, environment, good luck orange energy, heat,enthusiasm,playfulness purpleroyalty, nobility, ceremony, magic, mystery pinkfemininity, love, beauty

41. A B male female

42. Color Blindness Ishihara Test for Color Blindness About 12 - 20 percent of white males and a tiny fraction of females are color blind. Normal Color Vision Red-Green Color Blind Left Middle RightLeft Middle Right Top 25 29 45 25 Spots Spots Bottom 56 6 8 56 Spots Spots 1

43. small squares –same color or not?

44. theory .... • Edward E. Tufte (professor emeritus of statistics, graphic design, and political economy) • "The Leonardo da Vinci of data."New York Times • he coined the term "chartjunk“.

45. chartjunk • This chart shows only five hard-to-read numbers, 1, 2, 4, 8 and 16, but the digital file of the image is 11216 bytes (numbers) in size.

46. theory.... Tufte uses the term data-ink ratio and argues strongly against the inclusion of any non-informative decoration in visual presentations of quantitative information and claims that ink should only be used to convey significant data and aid in its interpretation.

47. Lurking behind chartjunk is contempt both for information and for the audience. Chartjunk promoters imagine that numbers and details are boring, dull, and tedious, requiring ornament to enliven. Cosmetic decoration, which frequently distorts the data, will never salvage an underlying lack of content. If the numbers are boring, then you've got the wrong numbers. Credibility vanishes in clouds of chartjunk; who would trust a chart that looks like a video game? Edward Tufte, "Envisioning Information", 1990

48. If a picture is not worth a 1000 words, to hell with it! Ad Reinhardt

49. Maps • maps show variations of a variable value with respect to an physical/geographic area • actual value of the response variable corresponds to: • height of the object (block, polyhedron, prism, spike,...) • color

50. Maps • problems: • height of the object  perspective • color  legend