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The Power of Information Visualization: An Introduction to i247

Learn about the definition and goals of information visualization through case studies and explore the transformative power of visualizing information. This course introduces the fundamentals of information visualization and its applications.

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The Power of Information Visualization: An Introduction to i247

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  1. i247: Information Visualization and PresentationMarti Hearst Course Introduction

  2. Outline • Definitions • The Power of Information Visualization • The Goals of Infoviz • Case Study: The Journey of the TreeMap • Course Outline • Administrivia

  3. What is Information Visualization? The depiction of information using spatial and graphical representations; Bringing information to life, visually.

  4. What is Information Visualization? Visualize: to form a mental image or vision of. Visualize: to imagine or remember as if actually seeing. American Heritage dictionary, Concise Oxford dictionary

  5. What is Information Visualization? “Transformation of the symbolic into the geometric” (McCormick et al., 1987) “... finding the artificial memory that best supports our natural means of perception.'' (Bertin, 1983)

  6. Visual Aids for Thinking • We build tools to amplify cognition. • Example: multiplication (Card, Moran, & Shneiderman.) • In your head, multiply 35 x 95 • Now do it on paper • People are 5 times faster with the visual aid

  7. The Power ofInfo. Visualization Images from yahoo.com

  8. The Power of Visualization 1. Start out going Southwest on ELLSWORTH AVE Towards BROADWAY by turning right. 2: Turn RIGHT onto BROADWAY. 3. Turn RIGHT onto QUINCY ST. 4. Turn LEFT onto CAMBRIDGE ST. 5. Turn SLIGHT RIGHT onto MASSACHUSETTS AVE. 6. Turn RIGHT onto RUSSELL ST. Image from mapquest.com

  9. The Power of Visualization Line drawing tool by Maneesh Agrawala http://graphics.stanford.edu/~maneesh/

  10. Visualization for Problem Solving Mystery: what is causing a cholera epidemic in London in 1854?

  11. Visualization for Problem Solving Illustration of John Snow’s deduction that a cholera epidemic was caused by a bad water pump, circa 1854. Horizontal lines indicate location of deaths. From Visual Explanations by Edward Tufte, Graphics Press, 1997

  12. Visualization for ElicitingKnowledge from Data

  13. Visualization for ElicitingKnowledge from Data

  14. Visualization for Clarification • London Subway Map Example • Abstract away details for easier understanding

  15. London Underground Map 1927

  16. London Underground Map 1990s

  17. From http://www.ideography.co.uk/

  18. Visualization: Two Primary Goals Analyze, Explore, Discover Explain, Illustrate, Communicate

  19. Case Study:The Journey of the TreeMap • The TreeMap (Johnson & Shneiderman ‘91) • Idea: • Show a hierarchy as a 2D layout • Fill up the space with rectangles representing objects • Nested rectangles indicated levels of hierarchy • Size on screen indicates relative size of underlying objects.

  20. Case Study:The Journey of the TreeMap (Johnson & Shneiderman ‘91)

  21. (Johnson & Shneiderman ‘91)

  22. Case Study:The Journey of the TreeMap • The TreeMap (Johnson & Shneiderman ‘91) • Idea: • Show a hierarchy as a 2D layout • Fill up the space with rectangles representing objects • Nested rectangles indicated levels of hierarchy • Size on screen indicates relative size of underlying objects.

  23. Early Treemap Applied to File System

  24. Treemap Problems • Too disorderly • What does adjacency mean? • Aspect ratios uncontrolled leads to lots of skinny boxes that clutter • Hard to understand • Must mentally convert nesting to hierarchy descent • Color not used appropriately • In fact, is meaningless here • Wrong application • Don’t need all this to just see the largest files in the OS

  25. Successful Application of Treemaps • Think more about the use • Break into meaningful groups • Make appearance more usable • Fix these into a useful aspect ratio • Do not use nesting recursively • Use visual properties properly • Use color to distinguish meaningfully • Use only two colors: • Can then distinguish one thing from another • When exact numbers aren’t very important • Provide excellent interactivity • Access to the real data • Makes it into a useful tool

  26. Squarified Treemaps Bruls, Huizing, van Wijk, 1999

  27. Squarified Treemaps Bruls, Huizing, van Wijk, 1999

  28. A Good Use of TreeMaps and Interactivitywww.smartmoney.com/marketmap www.smartmoney.com/marketmap

  29. Treemaps in Peets site

  30. Analysis vs. Communication • MarketMap’s use of TreeMaps allows for sophisticated analysis • Peets’ use of TreeMaps is more for presentation and communication • This is a key contrast

  31. Amanda Cox, Heather Fairfield, NY Times

  32. Amanda Cox, Heather Fairfield, NY Times

  33. Others: Analysis Monitoring Planning Communication Tufte: Description Exploration Tabulation Decoration Others: Aid to thinking Problem solving/Decision making Insight Clarifying Entertainment / Art Other Taxonomies of Goals Ideas from this slide from Stone & Zellweger

  34. Another way to think about it • Answer this question: Do you know the answer? • If yes, • Presentation, communication, education • If no, • Exploration, analysis • Problem solving, planning, • Aid to thinking, reasoning • Answer this question: Are you the creator or the viewer of the information? • Often there is a loop between analysis and presentation Ideas from this slide from Stone & Zellweger

  35. The Need for Critical Analysis • We see many creative ideas, but they often fail in practice • The hard part: how to apply it judiciously • Inventors usually do not accurately predict how their invention will be used • This course will emphasize • Getting past the coolness factor • Examining usability studies

  36. Open Issues • Does visualization help? • The jury is still out • Still supplemental at best for text collections • A correlation with spatial ability • Learning effects: with practice ability on visual display begins to equal that of text • Does visualization sell? • Jury is still out on this one too! But there are some success stories. • This is a hot area! More ideas will appear!

  37. Course Outline • Principles of Information Presentation • Principles of Visual Perception • Interactive Information Visualization • Project Design Reviews • Visual Explorations • Evaluating and Automating Visualizations

  38. What we will learn • Design interactive visualizations • Critique existing designs • Empirically evaluate existing designs • An HCI-based focus Slide adapted from Chris North's

  39. What we are not covering • Scientific visualization • Statistics • Cartography (maps) • Education • Games • Computer graphics in general • Computational geometry

  40. Administrivia • Order textbooks right away • Download and install software • Do readings/video watchings indicated by the course website: • http://courses.ischool.berkeley.edu/i247/s08/

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