1. SpaceTree An Interactive Visualization of Traditional Node-Link Tree Diagrams Jesse Grosjean Catherine Plaisant Ben Bederson Human-Computer Interaction Laboratory University of Maryland

2. Node Link Tree Diagrams Big Oil President Eastern Region Manager Western Region Manager North Region Manager Safety Manager Support Functions Facilities Engineer Operations Manager Drilling Manager HR Manager Land Manager IT Manager Familiar representation Shows tree topology well BUT: Inefficient use of screen space

3. SpaceTree Dynamic rescaling of branches to best fit available screen space based on focus. Preview icons to summarize the topology of hidden branches Smooth animation between views Integrated search and filter functions

4. Alternative Preview Icons

5. User Study 18 subjects, all used the 3 interfaces Order and task set counterbalanced 40 minute session SpaceTree MS Explorer Hyperbolic tree browser

9. Attractiveness (1=not cool at all, 9=very cool) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 ExplorerHyperbolic SpaceTree No significant difference between Hyperbolic and SpaceTree Subjective Preference: Attractiveness

10. Use (1=would not like to use, 9=very much like to use) 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 ExplorerHyperbolic SpaceTree No significant difference Preference for Future Use

11. Time to Return to Previously Visited Node 0.00 5.00 10.00 15.00 20.00 25.00 ExplorerHyperbolic SpaceTree Time is sec. SpaceTree sign. faster than Hyperbolic, Explorer fastest

12. Estimating Size of Subtrees Example: comparing 3 subtrees of 60, 300 and 160 nodes (SpaceTree also faster)

13. Estimating Size of Subtrees Example: comparing 3 subtrees of 60, 300 and 160 nodes (SpaceTree also faster)

14. Conclusions Preview icons and consistent layout improve node-link tree browsers Task analysis will help you chose the right browser www.cs.umd.edu/hcil/spacetree/ Partial support from Chevron-Texaco Participation of Jean-Daniel Fekete and Ben Shneiderman at HCIL, Cheryl Lukehart and Don Schiro at Chevron-Texaco.