Comprehending KnowledgeSpace Diagrams: Experiments and a Model

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Comprehending Knowledge-Space Diagrams
Experiments and a Model

• Christof Körner
• University of Graz

ERASMUS Intensive SeminarGraz 2005
Supported by
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Other Hierarchical Graphs
Computer File System
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More Hierachical Graphs
Organisation Chart
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More Hierachical Graphs
Preference Graph
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Visual Properties Planarity
Non-crossed
crossed
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Visual Properties Slopes
upright
slanted
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Visual Properties Levels
horizontal
non-horizontal
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Visual Properties and Graphs
Crossed, slanted, non-horizontal
Non-crossed, upright, horizontal
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Early Experiments Paradigm
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Early Experiments Results
Planarity Slopes Levels
Different Prior Knowledge
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Early Experiments Results
Planarity Slopes Levels
Number of Comparisons
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Early Experiments Discussion

• Planarity is the most important visual property
• Slopes and Levels have only a minor effect
• Planarity is independent of the other properties

• Question
• Where (and when) does planarity exert its
  influence?

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Recent Experiment Sequential Processing
The 3-Stage Model (Körner, 2004)
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Paradigm Sequence of Events
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Results
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Data Analysis Scanpath Decomposition

• When was the first object fixated? ? End of
  Stage 1
• When was the second object fixated? ? End of
  Stage 2
• What happens then? ? Start of Stage 3 ?
• When does the manual response occur?

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Results
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Results
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Results
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Discussion

• Is graph processing in 3 stages a waste of time?
• NO!
• Visual search for a target object amongst a set
  of distractor objects is highly efficient and
  effortless
• An additional search stage does not slow down
  graph processing much
• A pure reasoning stage can focus on the relation
  of the objects located earlier

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Summary Conclusions

• 3-stage model of sequential graph reasoning
  provides detailed account of the course of
  comprehension
• Model provides clear and testable predictions
• Empirical evidence supports the model
• Model needs to be tested more rigorously
• Model may be extended to other types of graphs

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Current Gaze Contingent Displays
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Current Gaze Contingent Displays
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Thank you!
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Results
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The Future Where do we go next?

• Search stages are functionally equivalent

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The Future - Results Pilot Study
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The Future Graphs and Visual Search
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The Future Where do we go next?

• Search stages are functionally equivalent
• Reasoning stage is separated