A Study on Multiple Views for Tree Visualization

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A Study on Multiple Views for Tree Visualization

• Soon Tee Teoh
• San Jose State University

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Questions

• Many different ways to represent a tree.
• What information can you get from one
  visualization?
• What information do you miss?
• Is information missed in one visualization
  obtainable in another?
• Do you get a wrong impression from a
  visualization?

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Study 1 File Directory Tree

• Group 1 was shown Horizontal Hierarchical tree
  and told to write what facts they were able to
  obtain.
• Then they were shown RINGS tree (together) and
  told to write the new facts that they were able
  to obtain.
• Group 2 was shown RINGS first, then Hierarchical
  tree.

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Results of Study 1

• Group 1 What can you see in RINGS better than
  you can see in Hierarchical Tree?
• Answer Can see structural information better
• Group 2 What can you see in Hierarchical Tree
  better than in RINGS?
• Answer Depth of a node

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Study 2

• Divided into 2 groups.
• Each person was shown a series of different
  visualizations of the Animal Tree.
• Group 1 was shown this order RINGS -gt Radial -gt
  Treemap -gt Hierarchical -gt RINGS
• Group 2 was shown this order Radial -gt RINGS -gt
  Hierarchical -gt Treemap -gt Radial
• Between each pair of visualizations, user was
  asked What can you see better in the new
  visualization?

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Results of Study 2

• RINGS vs. Radial tree
• Advantages of RINGS none
• Advantages of Radial mollusks, threadworms
• Treemap vs. Radial
• Advantage of Treemap Relative sizes of Level 3
  nodes
• Advantage of Radial Able to see ancestor of a
  node
• RINGS vs. Hierarchical
• Advantage of RINGS Able to see Birds better
• Advantage or Hierarchical Can perceive total
  number of descendents of a sub-tree
• Hierarchical vs. Treemap
• Advantage of Hierarchical Perceive depth of a
  node
• Advantage of Treemap Compare size of two nodes

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Conclusions I

• Global Tree Visualization
• We use Treemap and Radial Tree
• Treemap and Radial Tree used to show either a
  tree or a subtree, focuscontext not natural
• Complementary
• Treemap shows size comparison better
• Radial Tree shows relationships better

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Conclusions II

• Local Tree Visualization
• Use RINGS and Hierarchical Tree
• RINGS The only one that shows structural
  differences between children of Birds
• Hierarchical Can see immediate files
• RINGS Can see similar patterns
• Hierarchical Can see depth of a node
• Nodes in RINGS sorted by number of children while
  in Hierarchical sorted by number of descendents