Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Visualising Multiple Overlapping Hierarchies


Published on

My first workshop presentation, describing problems of multiple taxonomies in biology.

Published in: Technology, Education
  • Be the first to comment

  • Be the first to like this

Visualising Multiple Overlapping Hierarchies

  1. 1. Visualising MultipleOverlapping HierarchiesMartin Graham, Jessie Kennedy, & Chris Hand Napier University, Edinburgh
  2. 2. Overview Introduction Problem Domain Current visualisation techniques Proposed Techniques Prototype Conclusions
  3. 3. Introduction Taxonomy Royal Botanic Garden Edinburgh Multiple overlapping hierarchies In general occur where a hierarchical structure is re-organised Taxonomy (our domain) Document categorisation etc No current visualisations support them
  4. 4. What is a Taxonomy? A methodology for classifying data. In our case, botanical specimens. As knowledge increases or opinions change, new classification hierarchies (taxonomies) are published These taxonomies co-exist. They do not replace each other. Leads to accumulation of multiple overlapping taxonomies.
  5. 5. Multiple Classifications
  6. 6. Taxonomists need to.. Track a specimen across several classifications View the progress of a group of specimens across classifications Filter out unwanted pieces of information We require a visualisation that can help taxonomists perform these tasks.
  7. 7. Current paper-basedtaxonomy
  8. 8. The problem No current suitable paper-based method for inspecting multiple overlapping taxonomies Investigate current computer-based visualisations
  9. 9. Previous visualisations Visualisations have been used for viewing hierarchical structures, e.g. file directories Examples: Cone Trees - Robertson et al Information Pyramids - Andrews
  10. 10. Cone Trees © 1991 ACM - Cone Trees: Animated 3D Visualizations of Hierarchical Information - Copy by permission of the Association of Computing Machinery
  11. 11. Andrews’ InformationPyramids “Information Pyramids” is © IICM, Graz University of Technology, Austria
  12. 12. Issues for Single Trees Issues arising show that visualising even one tree has problems Leaves displayed - internal structure masked Space issues Occlusion when 3D used So visualising one tree is a problem
  13. 13. Visualisation techniques formultiple trees Two main techniques used: Animation - showing development over time Huang & Eades huge graphs • also Wittenburg’s TreeViewer Small Multiples - showing development over physical space Chi’s Evolution of Web Ecologies Treemaps - Shneiderman & Johnson
  14. 14. Huang’s on-line visualisationof a website © Dept. of Computer Science and Software Engineering, University of Newcastle, NSW, Australia
  15. 15. Chi et al’s Web EcologyViewer © User Interface Research Group - Xerox PARC
  16. 16. Multiple TreeMap Comparison © Human-Computer Interaction Laboratory, Dept. of Computer Science, University of Maryland, USA
  17. 17. Issues for multiple trees Animation Direct visual comparison between two states only. Works best for gradual changes, not new structures. Small Multiples Lack of space on-screen due to repeating data Lacks strong pre-attentive cues
  18. 18. The Problem to be visualised Need to develop appropriate visualisations to tackle these problems Time/space trade-off
  19. 19. Initial Design Sketch (1)
  20. 20. Initial Design Sketch (2) Ability to track a sub-tree (genus - grouping of specimens) across multiple hierarchies
  21. 21. Initial Design Sketch (3) Filter out unwanted pieces of information
  22. 22. Prototype
  23. 23. Conclusions Need for visualising multiple hierarchies Current visualisation techniques inadequate Initial solutions Continuing work Prototyping User evaluation/feedback
  24. 24. Acknowledgements Royal Botanic Garden, Edinburgh EPSRC