SIMS 247 Information Visualization and Presentation

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SIMS 247Information Visualization and
Presentation

• Prof. Marti Hearst
• January 25, 2002

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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

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What is Information Visualization?

• Transformation of the symbolic into the
  geometric''
• (McCormick et al., 1987)
• ... augmenting natural intelligence in the
  best
• possible way, ... finding the
  artificial memory that best
• supports our natural means of
  perception.''
• (Bertin, 1983)
• The depiction of information using spatial or
  graphical
• representations, to facilitate
  comparison, pattern
• recognition, change detection, and
  other cognitive skills that make use of the
  visual system.

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Information Visualization

• Problem
• HUGE Datasets How to understand them?
• Solution
• Take better advantage of human perceptual system
• Convert information into a graphical
  representation.
• Issues
• How to convert abstract information into
  graphical form?
• Do visualizations do a better job than other
  methods?

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Visualization Success Stories
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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.

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The Power of Visualization
Line drawing tool by Maneesh Agrawala
http//graphics.stanford.edu/maneesh/
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Visualization Success Story
Mystery what is causing a cholera epidemic in
London in 1854?
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Visualization Success Stories
Illustration of John Snows 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
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Visualization Success Stories
Illustration of John Snows 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
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Visualization in the Aftermath of 9/11
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Six Degrees of Mohamed Attahttp//business2.com/a
rticles/mag/0,1640,35253,FF.html
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US Terrorism Response Org Charthttp//www.cns.mii
s.edu/research/cbw/domestic.htmwmdchart
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US Terrorism Response Org Charthttp//www.cns.mii
s.edu/research/cbw/domestic.htmwmdchart
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Flash Animation of Flight Paths
http//www.usatoday.com/graphics/news/gra/gflight
path2/frame.htm
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Purpose of Information Visualization

• To help
• Explore
• Calculate
• Communicate
• Decorate

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Two Different Primary GoalsTwo Different Types
of Viz

• Explore/Calculate
• Analyze
• Reason about Information
• Communicate
• Explain
• Make Decisions
• Reason about Information

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Goals of Information Visualization

• More specifically, visualization should
• Make large datasets coherent
• (Present huge amounts of information compactly)
• Present information from various viewpoints
• Present information at several levels of detail
• (from overviews to fine structure)
• Support visual comparisons
• Tell stories about the data

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This Course

• Visualization of large, abstract datasets
• Examples
• text collections / digital libraries
• web clickstream data
• complex information systems
• your idea goes here

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Why Visualization?

• Use the eye for pattern recognition people are
  good at
• scanning
• recognizing
• remembering images
• Graphical elements facilitate comparisons via
• length
• shape
• orientation
• texture
• Animation shows changes across time
• Important to link with kinds of communication

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A Key Question

• How do we
• Convert abstract information into a visual
  representation
• While still preserving the underlying meaning
• And at the same time providing new insight?

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Key Tools

• Animation
• Using size to indicate quantity
• Using color for distinguishing / selection
• NOT FOR QUANTITY!!!!
• Brushing and Linking
• Providing multiple views

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The Need for Critical Analysis

• We see many creative ideas, but they often bomb
  in use
• The hard part how to apply it judiciously
• Inventors usually do not accuratly predict how
  their invention will be used
• This course will emphasize
• Getting past the coolness factor
• Examining usability studies

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Example of finding the right application

• The Treemap (Johnson Shneiderman)
• Idea
• Show a hierarchy as a 2D layout
• Size on screen indicates relative size of
  underlying objects

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Treemap applied to File System
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Treemap Problems

• Too disorderly
• What does adjacency mean?
• Aspect ratios uncontrolled leads to lots of
  skinny boxes that clutter
• Color not used appropriately
• In fact, is meaningless here
• Wrong application
• Dont need all this to just see the largest files
  in the OS

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Tennis Match Application
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File System Application
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Successful Application of Treemaps

• Think more about the use
• Break into meaningful groups
• Fix these into a useful aspect ratio
• Use visual properties properly
• Use color to distinguish meaninfully
• Only two colors can distinguish one thing from
  another
• Amount isnt very important
• Provide excellent interactivity
• Access to the real data
• Makes it into a useful tool

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TreeMaps in Action
http//www.smartmoney.com/maps
http//www.peets.com/tast/11/coffee_selector.asp
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A Good Use of TreeMaps and Interactivity
www.smartmoney.com/marketmap
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Treemaps in Peets site
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Analysis vs. Communication

• MarketMap use of treemaps allows for
  sophisticated analysis
• Peets use of treemaps is more for presentation
  and communication
• This is a key contrast for this course

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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!
• This is a hot area! More ideas will appear!

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What we are not covering

• Scientific visualization
• Statistics
• Cartography (maps)
• Education
• Games
• Computer graphics in general
• Computational geometry

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Readings

• Textbook Card, Mackinlay, and Shneiderman (Eds.)
  Information Visualization Using Vision to Think
• A course reader (not ready yet)
• I have a large collection of books that can be
  borrowed.
• There are many online resources

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Software

• We have special access to software
• Will mainly be on SIMS lab machines
• Spotfire
• Table lens (Eureka)
• Parallel Coordinates
• Polaris

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Prototyping Tools

• Flash or Python TK
• Good for prototyping animation
• Jazz toolkit
• Written in java supports zoom
• Polaris toolkit
• Can build up complex systems using XML or tcl
  scripting

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Class Structure

• A new topic each week
• Student run
• Lots of readings
• Two or three assignments (50 total)
• One final project (50)

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Each Week

• Two students make a presentation
• Lasts 1 to 1.5 hours
• Summary, synthesis, critical analysis of the
  contents of the readings
• Use the questions shown on a later slide
• Examples of relevant visualizations found on the
  web, in print, etc
• Suggestions for how the ideas could be used, or
  why they should not

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Each Week (cont.)

• Non-presenting students
• Read all but one of the assigned papers
• Write up one page
• The contents of the writeup will be determined in
  advance by the presenting students
• The presenting students will provide feedback on
  the other students writeups
• check, check-minus, check-plus

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Each Week (cont.)

• Prof will do one or more of
• Have a guest speaker
• Show an interesting video
• Bring up some interesting topic to discuss
• Ask other students to show an assignment they did
  
• (with advance warning)

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Key Questions to Ask about a Viz

• What does it teach/show/elucidate?
• What is the key contribution?
• What are some compelling, useful examples?
• Could they have been done more simply?
• Have there been usability studies done? What do
  they show?

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For Next Week

• (Prof will lecture once more)
• Do the following readings
• RIIV Chapter 1. Information Visualization
• Carlis, J. V., and Konstan, J.K., Interactive
  Visualization of serial periodic data.
• Bertin, Graphics and Graphic Information
  Processing
• Kosslyn, S. M., Understanding Charts and Graphs.
• J. Mackinlay Automating the Design of Graphical
  Presentations of Relational Information
• Lohse, G.L., Biolsi, K., Walker, N., and Rueter,
  H.H., A Classification of Visual Representations
• Optional Treemap paper