1. Information Visualization 2: Overview and Navigation
Chris North
cs3724: HCI

2. Review Shneiderman’s Info. Vis. mantra? Mapping data to graphics?
overview first, zoom&filter, details on demand
Mapping data to graphics?
1. data items to visual objects
2. data attributes to visual properties

3. Data a a a The Problem data data data detail zoom O+D F+C trans Screen

4. Typical Navigation
1D scrollbar 2D scrollbars
What’s
wrong?

5. Keyhole Problem Where am I? Where can I go? Where do I want to go?
How do I get there?
Lack of context, overview

6. Keyhole Problem

7. Context is Important!

8. Data a a a The Problem data data data detail zoom O+D F+C trans Screen

9. E.g: 3 Overviews of Text
(MS Word)
Advantages?

10. Visual Overview Show me the data!
Map, organization (spatial layout of concepts)
What information is (not) available?
Adds context info, relationships
Enables direct access
Encourages exploration
HCI metrics:
Improves user performance, learning time, satisfaction
Insight

11. Navigation Strategies
Detail Only
Overview+Detail
Multiple views
Zooming
Focus+Context
Distortion, fisheye

12. Zooming large 2D spaces Powers of 10

13. Zooming: 2D KidPad, HiNote, Jazz http://www.cs.umd.edu/hcil/jazz/
Semantic zooming:
Don’t just show things at different size
change objects to make sense
E.g. add/remove detail info
Powers of Ten
Controls?

14. Overview+Detail: 1D
SeeSoft

15. Overview+Detail: 2D Overview: Detail: Zoom factor = 5
Square in overview tightly-coupled to scroll bars of detail

16. Multiple levels = large scale
overview
intermediate view
intermediate view
detail view
Zoom factor = 125

17. Multiple Foci
Linkit

18. Focus+Context: 1D
Fisheye Menu:
Perspective Wall

19. Focus+Context: 2D

20. Comparison Zooming: Overview+Detail: Focus+Context:
Screen space efficient
Infinite scalability
Lose overview when zoom in
Overview+Detail:
Good scalability, chaining
Multiple foci
Disconnect between views, back-n-forth
Focus+Context:
Integrated overview with detail, connected
Least scalable
Distortion, overview unstable

21. Quiz
Spotfire?
TableLens?

22. Design Exercise