1. Information Visualization
David Akers · 07 November 2006

2. Definition [www.oed.com]
1. The action or fact of visualizing; the power or process of forming a mental picture or vision of something not actually present to the sight; a picture thus formed.
1883 Academy 14 July 31 Investigations into the phenomena of visualisation.
1884 GURNEY & MYERS in 19th Cent. July 72 In the next stage of visualisation the percipient sees a face or figure projected or dejected, as it were, on some convenient surface.
1894 Athenæum 10 Nov. 638/2 [The book had] a power of visualization that gave it a claim to real originality.
Ansel Adams:
This technical innovation, now a staple of photography, facilitated Adams' aesthetic practice, which he termed "visualization." The basic component of Adams' "expressive photography," visualization requires the photographer to capture his response to a particular scene, not simply reproduce the landscape before him. The fall of light, the play of shadows, the line of the horizon, the angle of a tree line or rock formation, should all express what the photographer feels about the view. Adams' visualization was a working method derived from his beloved mentor Alfred Stieglitz's credo that photographs are the visual equivalents of emotion and perception.

3. Definition [www.oed.com]
2. The action or process of rendering visible.
1936 Amer. Jrnl. Cancer XXVII. 49 The hexagonal tube offers distinct advantages with its flat sides permitting good visualization.
1960 New Scientist 28 July 305/3 Echo sounding is now being applied to the visualization of structures within the body.
1973 Nature 17 Aug. 410/1 Direct visualization of biological material at this level would tell us much about the structure and mode of action of macromolecules.
1982 Listener 23/30 Dec. 42/3 The cinematic visualisation of the script belongs entirely to Welles and his technicians.
Here the term visualization is used to describe anything done to make something visible.
Visualization is an active process used to reveal visual information. This definition gets at communicating information.

5. Challenger Disaster
Breaks up the damage into many types, doesn’t include temperature.
1 of 13 pages of material faxed to NASA by Morton Thiokol

6. Challenger Disaster
Shows only two of the launches (SRM 15 and SRM 22) where there were problems with blow-by..
In both cases there were problems, but the problems were worse in SRM 15
Conclusion – shouldn’t launch at low temps… (faulty – what about the rest of the data? What about things besides blow-by?)
Point – should always be careful to include evidence of failures *and* successes... The differences are the important part!
1 of 13 pages of material faxed to NASA by Morton Thiokol

7. Challenger Disaster E. Tufte, pp. 46-47 , Visual Explanations
Problems:
chartjunk
Order the o-ring problems by temperature
Show both problems and non-problems
Extend the scale to make the point that the launch was much colder than all the previous launches
E. Tufte, pp , Visual Explanations

8. Challenger Disaster
Redrawn by E. Tufte, p. 49 , Visual Explanations

9. Functions of visualizations
Communicate information to others
Make a point
Tell a story
Make decisions
Support analysis and reasoning
Answer a question
“One image = One diagnosis”
To explore and discover; encourage creativity
Look at things in a new way
“The purpose of computing is insight, not numbers” [R. Hamming]
Inspire
John Tukey, EDA, p. vi
“force us to notice what we never expected to see”

10. The Purpose of Data Visualization is to Help People Think and Communicate

11. Gulfs of Execution & Evaluation
Conceptual model
(Goals)
Real world (Interactions)
As simple as moving as pointing your finger to a target.
Example execution:
Manipulating a robot through a textual commands
Manipulating a robot through a telemanipulator
Example of evaluation
a set of data point shown as a table with 2 column?: are they correlated?
a graph showing the same data points are they correlated?
But also can lead to error:
Reading bearing on a non mercator projection,
False alignment, …
Execution
Norman 1986

12. Gulf of Evaluation Gulf Real world: Evaluation Conceptual
model: x,y correlated?

13. Gulf of Evaluation Gulf Real world: Evaluation Conceptual
model: x,y correlated?

14. Gulf of Evaluation Evaluation r = -.29 Gulf Real world: Conceptual
model: x,y correlated?

15. Gulf of Execution Execution Gulf Conceptual model: Draw a rectangle
Real world
Move 90 30
Rotate 35
Pen down …
Execution

16. Gulf of Execution Gulf Real world Conceptual model: Draw a rectangle

17. Visualization: A Double Gulf?
Visualization user
Visualization designer
Evaluation
Representation
Conceptual
model
Data
Visualization
Not in control of the Evaluation and Execution, but the correct pick for the representation and Manipulation can reduce the both gulf of Evaluation and Execution.
Previous lecture on the evaluation
Efficient
Accurate
What about the execution
grasp better understanding
Query the model
Compute
Search answer
Execution
Manipulation

18. Bad visualization? Visualization user Visualization designer
Evaluation
Representation
x,y
correlated?
Data

19. Better Visualization? Visualization user Visualization designer
Evaluation
Representation
x,y
correlated?
r = -.29
Data

20. Abstraction is key to design. This is one of the best examples
Abstraction is key to design. This is one of the best examples. First subway map to notice that public transit map doesn’t need to exactly follow the path that the trains/buses follow. What is important is the general direction & what are the stops. This makes is MUCH easier to read (you don’t need to know all the little wiggles).

21. Agrawala and Stolte, Rendering Effective Route Maps, SIGGRAPH 2001
Overlaid Route
Sketched Route
Find cognitive and perceptual principles
Optimize the visualization according to these principles
Agrawala and Stolte, Rendering Effective Route Maps, SIGGRAPH 2001

22. Matthew Ericson, NY Times
2004 presidential election
Matthew Ericson, NY Times

23. Matthew Ericson, NY Times
2004 presidential election
Matthew Ericson, NY Times

24. 2004 presidential election

25. From Cartography, Dent

26. Map scaled to airline fares
From Cartography, Dent

28. Phan et al. 2005

29. Describes Napoleon’s March to Moscow in “The War of 1812”
Drawn in 1861 by Charles Joseph Minard.
Combination of a map and a time series. Five variables are plotted: location, time, size
and temperature (Tufte includes direction).
Beginning at the left of the map is Polish-Russian border near the Neiman River. The
Thick band shows the number of soldiers in the army.
Napolean started with 422,000 men in June of 1812;
100,000 reached Moscow in September 1812;
Temperature vs. time is shown in the graph on the bottom. The highest temperature is
0 and it goes to -30. The time runs from October on the right to December on the left.
The crossing of the Berezina River was a particular disaster.
Image from
Text paraphrased from Tufte, VDQI, p 40.
Minard (1861)

30. Dynamic Queries
TimeSearcher: Hochheiser and Shneiderman 2001

31. DTI-Query [Akers et al. 2004, Sherbondy, et al. 2005]