Visualizing Uncertainty:Computer Science Perspective
Ben Shneiderman, Univ of Maryland, College Park
Alex Pang, Univ of California, Santa Cruz
National Academy of Sciences Workshop
March 3-4, 2005, Washington, DC
What do we mean by uncertainty?
Why is this an issue now?
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Sources of uncertainty
Measurement problems Ranges/SummariesMissing dataHuman ratingsPotential deceptionsPrivacy protectionRisk assessmentsForecasts
Scientific data Intelligence sources Statistical analyses Medical images Gene expression Simulations Financial models Weather Consumer ratings
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Visualizations
Text, statistical measures…
1D: Lists, documents, numeric ranges… 2D: Geographic Info 3D: Scientific Visualization
Multi-Variate: Information Visualization Temporal: Patient histories, web logs … Tree: Taxonomies, org charts, directories … Network: Social, communication…
Info
Viz
S
ciV
iz
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Text: Statistical uncertainty
Text
1D 2D 3D
Multi-V Temporal Tree Network
Frustration (N=372)
Time Variables
Time Lost (Incident) **.293
Time to Fix (Incident) **.233
Computer Years -.041
Hours per Week *-.124
* = p<.05 ** = p<.01
Poll Dems Reps
Bush 14% 81%
Kerry 79% 7% Margin of error +/- 3%
Rain inches
Reliability
SW 1.0 low
SE 1.5 high
NW 1.2 low
NE 0.8 med
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Risk/Danger vs. Trust/Validity/Security
Text
1D 2D 3D
Multi-V Temporal Tree Network
Risk
Municipal
Bonds
low
Blue Chip
Stocks
med
Tech
Stocks
high
Real Estate med
TerrorThreat levels
Highly About HighlyUnlikely Unlikely Even Likely Likely
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1D: Ranges, variations & forecasts
Text
1D 2D 3D
Multi-V Temporal Tree Network
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2D: Ball glyphs Delta (observation - forecast)
http://www.cse.ucsc.edu/research/slvg/assim.html
Text
1D 2D 3D
Multi-V Temporal Tree Network
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2D: Arrow glyphs (Direction & velocity)
http://www.cse.ucsc.edu/research/avis/unvis.html
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2D: Box glyphs
Schmidt et al., 2004, Underwater Environmental Uncertainty, IEEE CG&Ahttp://csdl.computer.org/comp/mags/cg/2004/05/g5056abs.htm
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2D: Grid with transparency/shading
Lefevre, Pfautz & Joneshttp://ams.confex.com/ams/pdfpapers/82400.pdf
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Off-the-shelf softwarecan give incorrect contourson data with lots of missingvalues.
Modifications to contouring algorithmto account for largenumber of missingvalues.
2D: Isolines with missing values
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2D: Pseudocolor shows mean values
Luo, Kao & Pang, 2003, EuroVishttp://www.soe.ucsc.edu/~pang/op.pdf
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2D: Darkness = uncertainty (high stddev)
Mean = hueSkew = 1/saturationStddev= 1/value
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2D: Separate layer
http://www.cse.ohio-state.edu/~bordoloi/Pubs/pdfCluster.pdf
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2D: Streamlines with binwise +
Luo, Kao & Pang, 2003http://www.soe.ucsc.edu/~pang/op.pdf
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2D: Weather forecast
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2D: NOAA Storm Prediction Center
http://www.spc.noaa.gov/products/
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2D: Dual views & grid lines
(Cedlink & Rhenigas, 2000)(Howard & MacEachren, 1996)
Dark shows pollution Dark shows Certainty
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(MacEachren et al., 1998)
Dual maps for Rate and reliability
Bivariate color scheme Double hatch shows unreliable
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http://svs.gsfc.nasa.gov/vis/a000000/a000000/a000010/index.html
Gray shows missing & interpolated value, superior to using black only
Twiddy, R., Cavallo, J., and Shiri, S. 1994. Restorer: A visualization technique for handling missing data. IEEE Visualization 94, 212-216
2D: Gray for missing & interpolation
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Crisp molecular surfaceProbe radius 1.4
Fuzzy molecular surfaceProbe radius 1.4
Crisp molecular surfaceProbe radius 5.0
Fuzzy molecular surfaceProbe radius 5.0
3D: Fuzzy molecular surface: HIV protease
Lee & Varshney (2002), UM Graphics and Visual Informatics Lab
http://www.cs.umd.edu/gvil
Text
1D 2D 3D
Multi-V Temporal Tree Network
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3D: Fuzzy molecular densities
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3D: Uncertainty ‘dust’
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3D: Color & opacity
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Text
1D 2D 3D
Multi-V Temporal Tree Network
Multi-V: Database/spreadsheet tables
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Text
1D 2D 3D
Multi-V Temporal Tree Network
Multi-V: Database/spreadsheet tables
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Temporal: Granularity of time
Text
1D 2D 3D
Multi-V Temporal Tree Network
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Text
1D 2D 3D
Multi-V Temporal Tree Network
Temporal: Granularity of time
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Text
1D 2D 3D
Multi-V Temporal Tree Network
Time
Uncertainty
Hi
Med
Low
Temporal: Granularity of time
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Text
1D 2D 3D
Multi-V Temporal Tree Network
Temporal: Granularity of time
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Tree: Topology, values & names
Text
1D 2D 3D
Multi-V Temporal Tree Network
Certainty
Hi
Med
Low
Very Low
- Gene Ontology- Tree of Life- Medical Subject Heading (MeSH)- Chain of command/Org chart
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Tree: Topology, values & names
Text
1D 2D 3D
Multi-V Temporal Tree Network
Certainty
Hi
Med
Low
Capacity
Hi
Med
Low
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Tree: Topology, values & names
Text
1D 2D 3D
Multi-V Temporal Tree Network
Certainty
Hi Med Low
Leland or Lee
Mike or Michael
Alex or Alan
Barbara
Scott
Ben or Benjamin
Diane or Di
Ed or Edward or Eddie
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Network: Social relationship
Text
1D 2D 3D
Multi-V Temporal Tree Network
http://prefuse.sourceforge.net/demos-radial.html
March 3-4, 2005NAS Workshop: Visualizing Uncertainty 38J.A. Brown, McGregor A.J and H-W Braun.
Network: Communication capacity
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Text
1D 2D 3D
Multi-V Temporal Tree Network
Certainty
Hi
Med
Low
Flow
Hi
Med
Low
Capacity
Hi
Med
Low
Network: Node & edge uncertainty
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Explore novel approaches to: Text: standard terms, percent, probabilities Box plots, whiskers, ranges Uncertainty glyphs, isoclines,… Contours, surfaces, volume rendering Hue, saturation, value, focus, haze, dust,… Dual views, probes Animation, blinking, shaking, flipping,… Sound, haptics,…
Next steps
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Next steps Heighten awareness of the problem among
public, professionals, researchers & developers Support multi-valued data representation standards Explore techniques for each data type Develop guidelines for implementers:
– Data formats– Interactive interfaces– Visual presentations
Develop human performance evaluation methods Publish benchmark datasets & evaluation metrics Form guidelines for how to
propagate/integrate uncertainty markers