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Lecture 08: Visualization Intro. September 30 , 2010 COMP 150-12 Topics in Visual Analytics. Lecture Outline. What is Visualization? Number Representations What is its value? Story telling or data exploration? Connecting data to visualization Bertin’s visual symbols What’s missing ?
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Lecture 08:Visualization Intro September 30, 2010 COMP 150-12Topics in Visual Analytics
Lecture Outline • What is Visualization? • Number Representations • What is its value? • Story telling or data exploration? • Connecting data to visualization • Bertin’s visual symbols • What’s missing? • Appropriateness? • Representation appropriateness • Biases
Define Visualization • Define visualization!
Examples of Visualization http://www.google.com/images?q=visualization
Is This a Visualization? 15,000 BC. Laxcaux, France
What about this? Hello World!
Define Visualization • “The communication of information using graphical representations” • Interactive Data Visualization (2009). Ward, Grinstein, Keim • “An external artifact supporting decision making” • Information Visualization (2004). Ware • “The use of computer-supported, interactive, visual representation of data to amplify cognition” • Readings in Information Visualization (1999). Card, Mackinlay, Shneiderman
Value of Visualization Possible Values of Visualization?
Value of Visualization • Story telling and/or data exploration?
Value of Visualization • Story telling and/or data exploration? Courtesy of Tableau
Value of Visualization What do you think?
Value of Visualization • Reduce Memory Load • Working memory is limited • Store information in the diagram • Reduce Search Time • Pre-attentive (constant-time) search process • Spatially-indexed patterns store the “facts” • Allow Perceptual Inference • Map inference to pattern finding
Number Representations • Zhang and Norman (1995). The Representation Of Numbers. Cognition.
Example: Arithmetic Slide courtesy of Pat Hanrahan
Example: Arithmetic Slide courtesy of Pat Hanrahan
Example: Arithmetic Slide courtesy of Pat Hanrahan
Distributed Cognition • Distributed cognition is a psychological theory that involves the coordination between individuals, artifacts and the environment. It has several key components: • Embodiment of information that is embedded in representations of interaction • Coordination of enaction among embodied agents • Ecological contributions to a cognitive ecosystem Courtesy of Wiki
Additional Thoughts? Slide courtesy of Pat Hanrahan
Connecting Data To Visualization • Data have attributes (dimensions) • Visualizations have attributes (dimensions) • Can the two map to each other? • Jacques Bertin, SemiologieGraphique (Semiology of Graphcis), 1967.
Elements of Visualization • Images are composed of marks: “ink”, graphical primitives Slide courtesy of Sara Su
Elements of Visualization Slide courtesy of Sara Su
Value (Intensity) Discrete or Continuous? Slide courtesy of Sara Su
Color (Hue) Discrete or Continuous? Slide courtesy of Sara Su
Visual Variables Slide courtesy of Sara Su
Appropriateness? • Which data dimension should be mapped to what visual variable?
Using Visualization to Influence? Image courtesy of http://sambbiblog.spaces.live.com
2008 Election Map Image courtesy of http://politicalmaps.org
2008 Election Map Image courtesy of http://politicalmaps.org
2008 Election Map Image courtesy of http://politicalmaps.org
Structure and Form Image courtesy of Barbara Tversky
Structure and Form Image courtesy of Barbara Tversky
Visual Metaphors Image courtesy Caroline Ziemkiewicz