Envisioning Information Lecture 7 – Interaction

1. Envisioning Information Lecture 7 – Interaction Ken Brodlie kwb@comp.leeds.ac.uk ENV 2006

2. Interaction • Major difference between paper and computer-based visualization is ability to interact with picture and alter the presentation of the data • Nice simple example is ‘Dancing with Histograms’ • Dix and Ellis http://www.comp.lancs.ac.uk/computing/users/dixa/papers/simple98/ • This lecture looks at two concepts: • Focus and context • Brushing ENV 2006

3. Focus and Context • A recurring problem in Information Visualization is lack of screen real estate • Challenge has been addressed in some innovative ways • Want to achieve: • Focus: to see detail of immediate interest • Context: to see the overall picture • Want to do this interactively… • Six approaches: • Distortion • Rapid zooming • Elision • Multiple windows • Use 3D (more space) • Use animation (more time) ENV 2006

4. Distortion: Bifocal Display • As name suggests, distortion achieves aim by magnifying focus area and demagnifying surrounding context • Probably the first suggestion was the bifocal display of Spence and Apperley (1982) • Play Spence bifocal_lens movie (http://www.iis.ee.ic.ac.uk/~r.spence/videos.htm) ENV 2006

5. Implemented as an image browser that scales different areas of image in different ways Chris North, Univ of Maryland Bifocal Display Available at: http://people.cs.vt.edu/~north/infoviz/ ENV 2006

6. A possible application is in map reading This London underground application was developed by Marcelo Cohen in Leeds Zoom / pan Focus /context Bifocal Display ENV 2006

7. Transforming the information space to the display space Visual transfer functions Display Space Display Space Information space Information space Bifocal display context focus What is the Bifocal Display Doing? Normal display ENV 2006

8. Developing the Idea • Card, Robinson and McKinlay developed the idea into the ‘Perspective Wall’ ENV 2006

9. The Perspective Wall 2D layout wrapped around a 3D structure • Space utilisation: • detail on centre • panel 3x size of • equivalent flat • wall fitting field of • view ENV 2006

10. Advantages: User can adjust ratio of detail to context Smooth animation helps user perceive object constancy Relationship between detail and context is consistent: objects bend around the corner Perspective Wall ENV 2006

11. In terms of transfer function, the situation is closer to the early Spence movie Perspective gives smoother transition from focus to context Display Space Information space Perspective Wall Perspective Wall context focus ENV 2006

12. Here is the same idea applied to menus Ben Bederson, University of Maryland See also: http://www.samuelwan.com/downloads/com.samuelwan.eidt/fisheyemenu/FisheyeMenuDemo.html FishEye Menus ENV 2006

13. Research pages at University of Maryland include a nice applet that allows you to compare different menu styles Arrow bar Scroll Bar Hierarchical FishEye Screenshots on next slide created from: http://www.cs.umd.edu/ hcil/fisheyemenu/ fisheyemenu-demo.shtml Comparison of Menu Styles ENV 2006

14. Menus hierarchical fisheye arrow scroll ENV 2006

15. Question • What are the disadvantages of the magnifying glass paradigm for providing focus and context? ENV 2006

16. This is a focus and context idea specifically aimed at tables Try applet at: http://www.inxight.com/products/sdks/tl/ Table Lens ENV 2006

17. Table Lens ENV 2006

18. Rapid Zooming Techniques • Idea is to allow rapid zooming between focus and context • Zoom in to focus, then out to context • Recent idea is SDAZ – Speed Dependent Automatic Zooming • Linked to scroll bar • Moving scroll bar fast will zoom out • Slowing scroll bar will zoom in again • See: http://www.cosc.canterbury.ac.nz/andrew.cockburn/liter.html ENV 2006

19. There is often a blurred distinction between zooming interfaces and distortion techniques Look at: http://www.cs.umd.edu/hcil/piccolo/index.shtml Rapid Zooming Interfaces New buzzword: ZUIs ENV 2006

20. Elision Techniques • Hide parts of a structure until they are needed • Widely used in graph drawing software for very large graphs • Have you seen this in xmdvtool? ENV 2006

21. Multiple views can also be used to provide focus and context Powerpoint uses this to good effect! Multiple Views ENV 2006

22. Move into 3D: Cone Trees • Using a third dimension allows us to prioritise the focus (foreground) without losing the context (background) • For large tree structures it is impossible to find sufficient screen space • Cone trees in 3D provide a solution • Here is a movie http://research.compaq.com/SRC/3Danimate/conetree.html ENV 2006

23. Adding a time dimension: RSVP • We can gain more space by adding time! • Recent Spence work addresses problem of browsing information spaces • Rapid Serial Visual Processing • To gain a quick view of what is available • Distinction between browsing and searching • Here is the movie(http://www.iis.ee.ic.ac.uk/~r.spence/videos.htm) ENV 2006

24. Browsing the Web • Spence has also turned his attention to browsing the web • On mobile devices! • Here is the movie(http://www.iis.ee.ic.ac.uk/~r.spence/videos.htm) ENV 2006

25. Brushing has become a fundamental concept in visualizing information Already encountered in xmdvtool Linking: Brushing ENV 2006

26. Selection from one view can be linked to a corresponding selection in another view Coordinated multiple views Linking: Coordinated Views ENV 2006

27. Many of the concepts we have talked about are brought together in the Snap-Together system of Shneiderman and North How many visualizations can you recognise here? Linking: Multiple Views http://www.cs.umd.edu/hcil/snap/ ENV 2006

28. Snap Together for Directories ENV 2006

29. Linking: Spence Attribute Explorer • Spence has also developed a tool called Attribute Explorer • Compare it with xmdvtool • Look for brushing concept • Here is the movie(http://www.iis.ee.ic.ac.uk/~r.spence/videos.htm) ENV 2006