1. SIMS 247: Information Visualization and Presentation Marti Hearst
Feb 25, 2004

2. Today Visualization for Analysis (Carlis & Konstan) Zooming
Focus + Context / Distortion-based Views
The Information Visualizer (Card et al.)

3. Visualization for Analysis
Carlis & Konstan, UIST 1998
For: data that is both periodic and serial
Time students spend on different activities
Tree growth patterns
Time: which year
Period: yearly
Multi-day races such as the Tour de France
Calendars arbitrarily wrap around at end of month
Octaves in music
Problem: How to find patterns along both dimensions?

4. Analyzing Complex Periodic Data
Carlis & Konstan, UIST 1998.

5. All 112 foods, alphabetical
Color corresponds to food type
Rings rather than blots to aid visibility
Carlis & Konstan, UIST 1998.

6. Analyzing Complex Periodic Data
12 most common foods
Consumption values for each month appear as spikes
Each food has its own color
Boundary line (in black) shows when season begins/ends
Carlis & Konstan, UIST 1998.

7. Analyzing Complex Periodic Data
Different use of the viz in the chimp domain
2 chimps (red and blue)
Length of line is size of the group they travel with
Top spiral is average size
Bottom spiral is max size
Carlis & Konstan, UIST 1998.

8. Analyzing Complex Periodic Data
Analyzing properties of sound
Carlis & Konstan, UIST 1998.

9. Analyzing Complex Periodic Data
Carlis & Konstan, UIST 1998.

10. Carlis & Konstan An excellent example of infoviz
Provides clarity about information that is not otherwise possible
Makes excellent use of visual principles
Color, size, position all used properly
Different features are easy to discriminate, do not interfere with one another
Applicable to many different types of problems
Different levels of complexity

11. Zooming, Focus + Context, and Distortion
Large amount of data in small space
Maximize use of screen real estate
Allow examination of a local area in detail within context of the whole data set
Today’s tools use one, two or all three of these techniques
Like the other InfoVis tools we are discussing this semester, this week’s readings discuss techniques that enable us to present a huge amount of data in a small amount of space (a monitor screen).
Example of tools:
[InfoZoom uses zoom, but not distortion or F+C (unless you count the animated zoom, which does show the relationship between the last view and the new view). Note that we’re not talking about this tool this week.]
Perspective wall uses F+C and distortion.
Pad++ uses all 3.
Fisheye menu uses F+C and distortion.
PhotoMesa uses zoom and F+C.
Data Mountain uses zoom and F+C.
Focus + Context is key to these visualizations.
Slide adapted from Hornung & Zagreus

12. Do These Work?
The existing studies indicate that we don’t yet know how to make the following work well for every-day tasks:
Pan-and-Zoom
3D Navigation

13. Zooming
Zoom in: ability to see a portion in detail while seeing less of the overall picture
Zoom out: see more of overall picture, but in less detail
Animation (also provides Focus+Context)
Animation: note that apps that have zoom tools (e.g., Acrobat) zoom in/out in a jumpy manner. In our opinion those tools don’t qualify as zoom in terms of InfoVis because they don’t have smooth transitions that help the user see how the new view and the previous view relate to each other.
Slide adapted from Hornung & Zagreus

14. Pad++ A toolkit An infinite 2D plane
(superceded by Piccolo, nee Jazz)
An infinite 2D plane
Can get infinitely close to the surface too
Navigate by panning and zooming
Pan:
move around on the plane
Zoom:
move closer to and farther
from the plane

15. Semantic Zooming Geometric (standard) zooming: Semantic Zooming:
The view depends on the physical properties of what is being viewed
Semantic Zooming:
When zooming away, instead of seeing a scaled-down version of an object, see a different representation
The representation shown depends on the meaning to be imparted.

16. Examples of Semantic Zoom
Infinitely scalable painting program
close in, see flecks of paint
farther away, see paint strokes
farther still, see the wholistic impression of the painting
farther still, see the artist sitting at the easel

17. Examples of Semantic Zoom
Information Maps
zoom into restaurant
see the interior
see what is served there
maybe zoom based on price instead!
see expensive restaurants first
keep zooming till you get to your price range
Browsing an information service
Charge user successively higher rates for successively more detailed information

18. The Role of Portals
All this panning and zooming can get confusing (maybe even dizzying)
Portals allow for zooming a small piece of the dataset while keeping everything else in the same position
Pad++ is one big stretchy sheet
A portal is more like a special window into a piece of the sheet
That window behaves independently of the rest

19. PadPrints
Graphical Multiscale Web Histories: A Study of PadPrints, R. Hightower, L. Ring, J. Helfman, B. Bederson, J. Hollan, Proc. Hypertext '98, Pittsburg, PA, 1998.

20. PhotoMesa http://www.cs.umd.edu/hcil/photomesa
Slide adapted from Hornung & Zagreus

21. PhotoMesa Interface Zooming is primary presentation mechanism
PhotoMesa: A Zoomable Image Browser Using Quantum Treemaps and Bubblemaps, B. Bederson, UCM UIST 2001
Zooming is primary presentation mechanism
Zoom in, zoom out on levels of thumbnails
Quickly drill down to individual picture (at full resolution)
Outline shows area of next zoom level
History of views
Thumbnail zooms up when hover w/cursor
Export images
Cluster by filename
Animated zoom shows how previous view relates to new view (like InfoZoom).
Zoom in, zoom out: left, right click
Drill down: 2x click
History: alt-left,right
Cluster by filename: creates a cluster for each unique word. Image appears once in each cluster that is a word in its filename.
Demo PhotoMesa v. 1.3.
Slide adapted from Hornung & Zagreus

22. PhotoMesa Goals Automatically lay out images
Use immediately – little setup time
Large set of images in context
Default groupings are by directory, time, or filename
No hierarchy
Makes managing photos difficult: can delete, but reorganization a problem
Can add metadata
Can start using right away, or can add metadata if you choose.
Slide adapted from Hornung & Zagreus

23. Bubblemaps Like Quantum Treemaps, elements guaranteed to be same size
Arbitrary shapes
No wasted space
May be harder to visually parse than QT
Abandon rectangular grouping – use arbitrary shapes
Because of irregular shape, may be harder to visually parse than quantum treemap
Slide adapted from Hornung & Zagreus

24. How to Pan While Zooming?

25. How to Pan While Zooming?

26. Navigation in Pad++ How to keep from getting lost?
Animate the traversal from one object to another using “hyperlinks”
If the target is more than one screen away, zoom out, pan over, and zoom back in
Goal: help user maintain context

27. Speed-Dependent Zooming
Speed-dependent Automatic Zooming for Browsing Large Documents, T. Igarashi, K. Hinckley, UIST 2000.
Navigation technique that integrates rate-based scrolling with automatic zooming.
Adjust zoom level automatically to prevent “extreme visual flow”
Automatically zoom out when going fast, zoom in when slowing down
Uses semantic zooming to provide context
Applied to
Large Documents (successful in a small study)
Image Collection (not successful)
Maps (mixed, needs work)
Dictionary (not successful)
Sound Editor (not successful)
Demo and Movie:

28. Is it useful? Is panning and zooming useful?
Is it better to show multiple simultaneous views?
Is it better to use distortion techniques?
Would keeping a separate global overview help with navigation?

29. Study of Overview + Detail
K. Hornbaek et al., Navigation patterns and Usability of Zoomable User Interfaces with and without an Overview, ACM TOCHI, 9(4), December 2002.
A study on integrating Overview + Detail on a Map search task
Incorporating panning & zooming as well.
They note that panning & zooming does not do well in most studies.

30. Overview + Detail
K. Hornbaek et al., Navigation patterns and Usability of Zoomable User Interfaces with and without an Overview, ACM TOCHI, 9(4), December 2002.

31. Overview + Detail Results seem to be
K. Hornbaek et al., Navigation patterns and Usability of Zoomable User Interfaces with and without an Overview, ACM TOCHI, 9(4), December 2002.
Results seem to be
Subjectively, users prefer to have a linked overview
But they aren’t necessarily faster or more effective using it
Well-constructed representation of the underlying data may be more important.
More research needed as each study seems to turn up different results, sensitive to underlying test set.

32. Distortion-based Techniques
Leung & Apperley:
Unified theory of distortion techniques
Techniques aim to solve problems of presenting large amounts of data in a confined space.
“…stretchable rubber sheet mounted on a rigid frame”
Stretching = Magnification
Stretching one part must equal shrinkage in other areas
Slide adapted from Hornung & Zagreus

33. Piecewise Non-Continuous Magnification Functions
Bifocal Display, Perspective Wall
Bifocal Display
Perspective Wall
Slide adapted from Hornung & Zagreus

34. Bifocal Display
Combination of detail view and two distorted side views
Can be applied in 2D
Since the corners are distorted by the same amount in x and y, it’s just scaled, not distorted
Slide adapted from Hornung & Zagreus

35. Perspective Wall
Similar to Bifocal, except demagnifies at increasing rate, while Bifocal is constant
Visualizes linear information such as timeline
Adds 3D but uses excess real estate on screen
Slide adapted from Hornung & Zagreus

36. Continuous Magnification Functions
Fisheye View, Polyfocal Display
Can distort boundaries because applied radially rather than x y
1D Fisheye
2D Polyfocal
Slide adapted from Hornung & Zagreus

37. Fisheye View Thresholding
Information elements have numbers based on relevance and distance from point of focus
Value then determines what information is to presented or suppressed
Polar Fisheye View
Image from Shishir Shaw
University of Texas, Austin
Slide adapted from Hornung & Zagreus

38. Fisheye Menu
Fisheye Menus, B. Bederson, in the Proceedings of ACM UIST 2000, pp
Dynamically change the size of a menu item to provide a focus area around the mouse pointer, while allowing all menu items to remain on screen
All elements are visible but items near cursor are full-size, further away are smaller
“Bubble” of readable items move with cursor
Slide adapted from Hornung & Zagreus

39. Fisheye Menu
Slide adapted from Hornung & Zagreus

40. Fisheye Menu Distortion Function Alphabetic Index Maximum font size
Focus length (number of items at full size)
Together these control the trade-off between the number of items at full size and the size of the smallest item
Focus length  small items  distortion 
Alphabetic Index
Indexes can decrease search time
Index is positioned so that if cursor is aligned with it, the item will be the first one for that letter
Initial design had current position, but this was confusing because it moved
Slide adapted from Hornung & Zagreus

41. Focus Lock
Item are difficult to select because small mouse movements result in change of focus
“Focus Lock” allows user to freeze focused area and move mouse freely
If cursor moves outside focus area, the area will expand, and perhaps push ends off the screen
Slide adapted from Hornung & Zagreus

42. Evaluation Small 10 person test, ½ programmers Results
Compared hierarchy, fisheye, scrollbar, and arrow bar (scrolling arrows)
Looking for trends
Results
Hierarchy was best for goal-directed task
Fisheye preferred for browsing
Not significantly though
Non-programmers rated it much lower than programmers
Only one person discovered Focus Lock
Index was thought to be interactive
Slide adapted from Hornung & Zagreus

43. Polyfocal Display Highest peak is focus of display
Distorts shape of boundaries
Troughs surrounding peaks are highly distorted and can effectively be shrunk to nothing
Slide adapted from Hornung & Zagreus

44. Comparisons Bifocal View Polyfocal View
Slide adapted from Hornung & Zagreus

45. Focus + Context Can go hand-in-hand with distortion – like fisheye
Works with zooming if animated – Photomesa
“Allows dynamic interactive positioning of the local detail without severely compromising spatial relationships.”
Leung & Apperley
“One challenge in navigating through any large dataspace is maintaining a sense of relationship between what you are looking at and where it is with respect to the rest of the data.”
Bederson & Hollan
Slide adapted from Hornung & Zagreus

46. Robertson, Card & Mackinlay
The Information Visualizer
Pioneered many Infoviz concepts
Definition
“Information Visualization is an attempt to display structural relationships and context that would be more difficult to detect by individual retrieval requests.”
Tech advances: Faster computer processing, low-cost memory and storage means that UI can be robust
Demand for info: massive increase in available info
1990s: info access will shape the successor to the desktop metaphor
Slide adapted from Hornung & Zagreus

47. Information Workspace
Workspace for information access
Slide adapted from Hornung & Zagreus

48. Information Workspace
Low-cost, immediate access to stored objects
Exploits power of new computers
Intends to answer demand for information management applications
Information’s “cost structure”
Intends to support emerging application demand to retrieve, store, manipulate, and understand large amounts of information. Precision, recall are important but also desire to reduce time cost of information, increase scale of info that can be handled at one time.
Info “cost structure”: Goal is to increase information access per unit cost.
System is “oriented toward the access and visualization of abstract nonphysical information of the form that knowledge workers would encounter.”
Slide adapted from Hornung & Zagreus

49. Large workspace Add virtual screen space Increase density
Rooms
Extend the “WIMP” desktop metaphor
Increase density
Animation
3D perspective
Increase real-time interaction between user and system
Visual Abstractions
Shift cognitive load to application
Abstract information structures speed user’s ability to assimilate and retrieve information
Large workspace: add virtual screen space using Rooms system. Goal is to increase density of information using animation and 3D perspective.
WIMP: Windows-Icons-Menus-Pointing
Slide adapted from Hornung & Zagreus

50. 3D Navigation Walking Metaphor Point of Interest Logarithmic Flight
Object of Interest Logarithmic Manipulation
Doors
Overview
Walking metaphor: require rapid and controlled, targeted 3D movement (as discussed in last week’s animation segment).
POI: Also discussed last week, this involves picking a target and moving the view towards it: rapidly when far from the target, slowing as we approach it.
OOI: similar to POI, but moving objects around, rather than moving toward a target.
Doors: moving from one visualization to another.
Overview: see all visualizations simultaneously
Slide adapted from Hornung & Zagreus