Tracing Tuples Across Dimensions
A Comparison of Scatterplots and Parallel Coordinate Plots
Xiaole Kuang (Master student, NUS)Haimo Zhang (PhD student, NUS)Shengdong (Shen) Zhao (Faculty member, NUS) Michael J. McGuffin
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(Faculty member, École de technologie supérieure)
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The Last Talk of The Last Session of
The Last Day!
Welcome to
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of
Vienna
Singapore
9697 km
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Vignette (CHI ‘12)SandCanvas (CHI ‘11)MOGCLASS (CHI ‘11)Magic Cards (CHI ‘09)
earPod (CHI ‘07)Zone & Polygon Menu (CHI ‘06)
Elastic Hierarchy (InfoVis ‘05)
Simple Marking Menu (UIST ‘04)
Systems, Tools, Interaction Techniques
Visualization Techniques for Multi-Variate Data
Scatter Plot (SCP)
Parallel Coordinate Plot
(PCP)
Scatter Plot Matrix (SPLOM)
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Why PCP vs. SCP?Both techniques are popular!Yet, we know very little about their comparative advantages.
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Viau et al., TVGC10
Yuan et al., TVGC09
Claessen & van Wijk, TVGC11
We need more systematic evaluations between PCP & SCP!
Basics of Evaluation Research question• What’s the comparative advantages
between PCP & SCP for certain tasks?
Task Independent variablesDependent variables
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Basics of Evaluation Research question• What’s the comparative advantages
between PCP & SCP for certain tasks?
Task Independent variablesDependent variables
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Basic Analytical Tasks
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serves as a subtask for many other tasks
Amar et al.: Low-level components of analytic activity in information visualization. InfoVis05, 111–117.
(Holten & van Wijk, EuroVis10)
(Li et al., InfoVis10)
PCP is inferior than SCP
Value Retrieval TaskDefinition: • Given the numerical value of one attribute
of a data tuple, find the numerical value of another attribute of the same data tuple.
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Multi-Variate Data Tuple (X1, X2, X3, …. , Xn)
a ?
Basics of Evaluation Research question• What’s the comparative advantages
between PCP & SCP for certain tasks?
Task Independent variablesDependent variables
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Independent Variables
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TechniqueParallel Coordinate Plot (PCP)
Scatter Plot (SCP)
X2
X1
X3
X2
X4
X3
X1
X2
X3
X2
X4
X2
X 2X 1
X 2X 3
X 4X 3
SCP-rotated (Qu et al., TVCG07)
SCP-common (SPLOM)
SCP-staircase (Viau et al., TVCG10)
Independent Variable – 4 Technique
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PCP
SCP-common(i.e., SPLOM)
SCP-rotated(i.e., Qu et al., TVCG07)
SCP-staircase(i.e., Viau et al., TVCG10)
Additional Independent Variables
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X2
X1
X3
X2
X4
X3
Number of Dimensions
X2
X1
X3
X2
X4
X3
X5
X4
Data Density
X2
X1
X3
X2
X4
X3
Independent Variables• Technique• Dimension• Density
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Dependent Variables• Completion time• Error distance
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Experiment Demo
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Experiment 1 Design 12 participants× 4 visualization techniques (PCP, SCP-common, SCP-rotate, SCP-standard) × 3 levels of data dimension (2D, 4D, 6D) × 3 levels of data density (10 tuples, 20 tuples, 30 tuples)× 3 repetitions of trials = 1296 trials in total.
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Seco
nds
SCP-rotate
SCP-common SCP-staircase
PCP
Overall Results
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Best Good
Poor
Completion Time Error Distance
Erro
r D
ista
nce
SCP-rotate
SCP-common SCP-staircase
PCP
Poor
Good
Poorer
1st Take-away Lesson
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PCP
SCP-common(i.e., SPLOM)
SCP-rotated(i.e., Qu et al., TVCG07)
SCP-staircase(i.e., Viau et al., TVCG10)
PCP vs. SCP-common
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PCP vs. SCP-common
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Density
Performance Difference
PCP vs. SCP-common
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Density
Performance Switch Order
Important Observation
There seems to be a
Density & Number of Dimension Trade-off
between PCP & SCP-common!
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Experiment 2× 18 participants
× 2 techniques (PCP, SCP-common)
× 3 dimensions (4D, 6D, 8D) [2D, 4D, 6D in Exp. 1]
× 3 densities (20 tuples, 30 tuples, 40 tuples) [10, 20, 30 in Exp. 1]× 5 trials for each combination
= 1620 trials in total.25
Results – Completion Time
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Overall result for Exp. 2SCP-common (15.41s) PCP (18.23s)
Result in Exp. 1SCP-common (12.02s) PCP (8.99s)
fasterfaster
Trade-off between number of dimensions & data density
Dimension Density
Results – Error Distance
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Trade-off between number of dimensions & data density
Dimension Density
Take-away LessonsThe value retrieval performance of PCP increases depending on dimensionality.The performance of SCP-common seems independent of dimensionality.
Increasing density affects the performance of PCP more than it affects SCP-common.
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Dimension
Density
Let’s Recap the Take Away-Messages and Ask
Why1) Both SCP-rotate and SCP-staircase are inferior for value retrieval task
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Let’s Recap the Take Away Messages
2) Performance trade-off between PCP & SCP-common for both dimensionalities and data density.• PCP increases depending
on dimensionality. • SCP-common
performance seems to be independent.
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Let’s Recap the Take Away Messages
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10 tuples
40 tuples
2) Performance trade-off between PCP & SCP-common for both dimensionalities and data density.• PCP increases depending
on dimensionality. • SCP-common
performance seems to be independent.
• Increasing density affects the performance of PCP more than it affects SCP-common.
Conclusion and Future Work
Our study helps to understand the comparative advantages between PCP & SCP
However, this is only a starting point, 32
The Grand VisionIdeally, this problem can be solved by …
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InfoVisevaluation
package
Results/Recommendations
AcknowledgmentThis research is supported by:
The National University of Singapore Academic Research Fund R-252-000-375-133
and by:
The Singapore National Research Foundation under its International Research Centre @ Singapore Funding Initiative and administered by the IDM Programme Office.
Q & A
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Elastic Hierarchy (InfoVis ‘05)
Tracing Tuples Across Dimensions (EuroVis ‘12)
End
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