Information Visualization on Large Displays

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Information Visualization on Large Displays

• Readings for today
• 1. Visual Scalability
• 2. Large Displays Will it ever be enough?

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What is Information Visualization?
(From Dr. Chris Norths cs5764 class slides)

• The use of computer-supported, interactive,
  visual representations of abstract data to
  amplify cognition
• Card, Mackinlay, Shneiderman

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Visual Scalability

• Authors Eick and Karr

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What is Visual Scalability?

• Definition Capability of visualization tools
  effectively to display large datasets
• Measurement
• Responses F(factors, data)
• Modest approach
• database metrics
• visualization characteristics

Discussion Question 1 How might using the same
visualization on a larger display change user
insights?
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Factors Affecting Visual Scalability

• Human Perception
• Monitor Resolution
• Visual Metaphors
• Interactivity
• Data Structures and Algorithms
• Computational Infrastructure

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Perception and Resolution

• 6.5 Million Perceivable Pixels
• Want to See Both Details and the Structure
• Monitor Resolution is the Limiting Factor

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Bar Chart Attributes/colors Number of bars
Matrix View Glyph size Aspect ratio
Landscapes Glyph size Aspect ratio 3D Occlusion
Network Views Connectivity Distortion
Scatterplots Over plotting
Histograms Number of bins
Discussion Question 2 Which scalability problems
go away with a larger display?
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Data Sheets Navigability
ParaBoxes Over plotting
Time Tables Over plotting
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Interactivity

• Panning Zooming
• Overview Detail (301) eliminates scrollbar
• Zoom factor 51

• Focus Context
• Distortion
• Zoom factor 51

• Identification and Selection
• Automatic Aggregation
• Brushing

Discussion Question 3 How might pz or od be
implemented for large displays?
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Increasing Visual Scalability

• Aggregation
• Improved Visual Metaphors
• Level of detail rendering (semantic zoom)
• Cutting plane
• Reduce number of labels
• Draw significant points last
• Jittering

Discussion Question 4 How does computational
aggregation compare to visual aggregation? Which
is more accurate?
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Increasing Visual Scalability (cont.)

• Exploiting Interactivity
• Larger views, time as a dimension
• Continuous zoom/zoom bars
• Rendering progressively less detail
• Hiding unselected items
• Multiple Perspectives
• Strengths of each
• Central view - overview
• Supporting views- act as filters

Discussion Question 5 With multiple perspectives
on a large display, what problems would we
have? How would interaction (such as brushing)
change?
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Discussion Questions

• How might using the same visualization on a
  larger display change user insights?
• Which scalability problems go away with a larger
  display?
• How might pz or od be implemented for large
  displays?
• How does computational aggregation compare to
  visual aggregation? Which is more accurate?
• With multiple perspectives on a large display,
  what problems would we have? How would
  interaction (such as brushing) change?
• Visual encoding the same on small and large
  displays?

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Large Displays Will it ever be enough?

• Authors May and Thomas

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Background

• InfoVis 05 Workshop
• PNNL
• HI-Space Human Information Workspace
• recognizes multiple simultaneous hands
• wall is primarily only a display surface
• Video

Discussion Question 1 What are some of the
tradeoffs between having controls on/off a large
display?
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Current Research Trends

• Most Visualizations Optimized for
• Desktop displays
• Individual interaction
• Trend Toward
• PDAs and wristwatches
• privacy
• Full-wall displays
• displaying a greater number of pixels on a
  surface is only a small piece of the solution"

Discussion Question 2 How do you create
visualizations that scale from tiny to huge
screens? Why would we want such an application?
What can designing for a tiny screen teach us
about our 1-monitor box?
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Possibilities to Investigate

• How do we take advantage of a wider field of
  view?
• Visual and interactive metaphors that take
  advantage of proprioceptive meaning behind
  spatial information
• Interaction techniques for large displays
• Collaborative visualization on large displays

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Discussion Questions

• What are some of the tradeoffs between having
  controls on/off a large display?
• How do you create visualizations that scale from
  tiny to huge screens? Why would we want such an
  application? What can designing for a tiny screen
  teach us about our 1-monitor box?
• What types of datasets/information visualization
  tasks would most benefit from a larger display?
• Final Question Is a display ever too big?