Post on 14-Dec-2015
Cambridge, Massachusetts
Perception of Elementary Graphical Elements in Tabletop and Multi-Surface Environments
Daniel Wigdor, Chia Shen, Clifton Forlines, Ravin Balakrishnan
CHI 2007
Department of Computer Science, University of Toronto
Acknowledgements
• John Barnwell• John Hancock• MERL & DGP Lab members• Experiment participants
In-Plane Rotation
In-Plane Rotation
NOT THIS PAPER
Planar Rotation
Planar Rotation
Planar Rotation
Planar Rotation
Information Graphics
Information Graphics
Encoding & Decoding
15 2823 52
Encoding & Decoding
15 2823 52
Encode
Encoding & Decoding
15 2823 52
Encode
Decode
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Cleveland and McGill: Elementary Perceptual TasksBertin: Visual Variables
Visual Variables
Visual Variables • Colour
Visual Variables • Colour
Visual Variables • Colour
Visual Variables • Colour
Visual Variables • Colour• Position
Visual Variables • Colour• Position
Visual Variables • Colour• Position• Slope
Visual Variables • Colour• Position• Slope
Visual Variables • Colour• Position• Slope
Visual Variables • Colour• Position• Slope
Visual Variables • Colour• Position• Slope
Visual Variables • Colour• Position• Slope• Length
Visual Variables • Colour• Position• Slope• Length
Visual Variables • Colour• Position• Slope• Length
Visual Variables • Colour• Position• Slope• Length• Area
Visual Variables • Colour• Position• Slope• Length• Area
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Answer: 38%
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Answer: 38%
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Modulus:
Stimulus:
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Answer: 40%
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Answer: 40%
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Answer: 67%
Visual Variables • Colour• Position• Slope• Length• Area• Angle
Modulus:
Stimulus:
Answer: 67%
Visual Variables • Colour• Position• Slope• Length• Area• Angle
57
Poor Elementary Perception
58
Slope vs Position
59
Slope vs Position
Experimental Task (Cleveland & McGill)
Experimental Task (Cleveland & McGill)
Experimental Task (Cleveland & McGill)
Experimental Task (Cleveland & McGill)
Conclusions (Cleveland & McGill)
• Error correlated with distance• Rank order of elementary tasks:
1. Position, common scale2. Position, identical nonaligned scales3. Length4. Angle5. Slope6. Area7. Volume, Density, Colour saturation8. Colour hue
Graphical Perception on a Rotated Plane
Vs.
Our Visual Variables:
Experimental Task Example: Line Length
Experiment 1: Single-Screen Comparisons
90° (Vertical)
60°
30°0° (Tabletop)
Hypotheses
I. As the display is tilted, the accuracy of relative magnitude judgements decreases.
Hypotheses
I. As the display is tilted, the accuracy of relative magnitude judgements decreases.
0
2
4
6
8
10
12
14
90 60 30 0
Error %
Err
or
Display Angle
Vertical Tabletop
Hypotheses
II. The up/down distance between objects is positively correlated with the increase in error in magnitude judgements due to screen angle.
Up/DownDistance
ERROR
0
2
4
6
8
10
12
14
16
0cm 14cm 28cmUp/Down Distance
Err
or
: l
Ju
dg
ed
- A
ctu
al
|
90 degrees
60 degrees
30 degrees
0 degrees
Hypotheses
II. The up/down distance between objects is positively correlated with the increase in error in magnitude judgements due to screen angle.
Tabletop
Vertical
Hypotheses
III. Different visual variable types have differing increases in the error in judgements.
Hypotheses
III. Different visual variable types have differing increases in the error in judgements.
0
5
10
15
20
25
0cm 14cm 28cm
Up/Down Distance
Err
or:
| J
ud
ge
d -
Ac
tua
l|
Length (V)
Length (H)
Angle (V)
Angle (H)
Position (V)
Position (H)
Slope
Area
Hypotheses
IV. Sideways presentations of objects experience less error in magnitude judgements due to screen angle than upright presentations.
Hypotheses
IV. Sideways presentations of objects experience less error in magnitude judgements due to screen angle than upright presentations.
0
5
10
15
20
25
Upright Sideways
Length
Angle
Position
Err
or
Hypotheses
V. There will be no effect for side-to-side distance on the accuracy of magnitude perception.
Side-to-sideDistance
Hypotheses
V. There will be no effect for side-to-side distance on the accuracy of magnitude perception.
Side-to-sideDistance
slope
area
position
length
angle
Rank Ordering of Visual Variable Perceptibility
Vertical Ranking: Tabletop Ranking:
position (upright)
length (upright)
angle (upright)
slope
area
position (sideways)
length (sideways)
angle (sideways)
position (upright)
length (upright)
angle (upright)
slope
area
position (sideways)
length (sideways)
angle (sideways)
length (upright)
angle (upright)
slope
area
position (sideways)
length (sideways)
angle (sideways)
position (upright)
Rank Ordering of Visual Variable Perceptibility
Vertical Ranking: Tabletop Ranking:
Multi-Surface Environments
Experiment 2: Apparatus
Hypotheses
I. There is an increase in error when comparing visual variable magnitudes between upright and tabletop displays versus comparing on displays of a single orientation.
Hypotheses
I. There is an increase in error when comparing visual variable magnitudes between upright and tabletop displays versus comparing on displays of a single orientation.
Hypotheses
II. The error increase when comparing between displays is unevenly distributed across visual variable types.
Hypotheses
II. The error increase when comparing between displays is unevenly distributed across visual variable types.
0
5
10
15
20
25
30
Upright &
Upright
Upright &
Tabletop
Length (U)
Length (S)
Angle (U)
Angle (S)
Position (U)
Position (S)
Slope
Area
Hypotheses
III. The size of the error on the mixed-orientation condition is larger than the largest errors in the previous experiment.
Hypotheses
III. The size of the error on the mixed-orientation condition is larger than the largest errors in the previous experiment.
Recommendations
• Mixed-orientation screen comparisons are hard• Ordered list (different than before):
1. length (sideways)
2. length (upright)
3. position (sideways)
4. angle (sideways)
5. area
6. angle (upright)
7. position (upright)
8. slope
Conclusions
• Don’t compare across display orientations• Special visualisations for tabletops & multi-surface spaces
Future Work
Σ= ?
Questions?
Experiment 1 Design
12 participants x
4 display angles x
4 visual variables (per participant) x
3 modulus positions x
9 stimulus positions x
3 magnitude estimates =
15,552 total comparisons
Experiment 2 Design
8 participants x
2 display angles x
8 visual variables x
31 magnitude estimates =
3,968 total comparisons