11. 11
« Without looking at your abdomen,
how would you draw the number two on it
with your right hand? »
12. User experiment
Inversion relative to vertical axis
No
Yes No
Yes
Inversion relative to horizontal axis
A B
C D
12
Two
• 12 users
• 2 factors: nature x presentation
• Subjective preferences questionnaire
13. Experimental design
13
Up Up
Right
Right Down
Right
Down Down
Left
Left Up
Left
One Two Three Four Five Six Seven Eight Nine Zero
Textual Graphical Textual Graphical
Directional Material
Digit Material
14. Possible spatial representations
14
Inversion relative to vertical axis
No
Yes No
Yes
Inversion relative to horizontal axis
A B
C D
15. Possible spatial representations
15
Inversion relative to vertical axis
No
Yes No
Yes
Inversion relative to horizontal axis
A B
C D
16. Possible spatial representations
16
Inversion relative to vertical axis
No
Yes No
Yes
Inversion relative to horizontal axis
A B
C D
17. Rates of inversions relative to axes
17
Digit Direction
0.4
0.2
0.0
Graphical Textual Graphical Textual
Axis
Horizontal
Vertical
18. Rates of inversions relative to axes
18
Digit Direction
0.4
0.2
0.0
Graphical Textual Graphical Textual
Axis
Horizontal
Vertical
19. Rates of inversions relative to axes
19
Digit Direction
0.4
0.2
0.0
Graphical Textual Graphical Textual
Axis
Horizontal
Vertical
20. Rates of inversions relative to axes
20
Digit Direction
0.4
0.2
0.0
Graphical Textual Graphical Textual
Axis
Horizontal
Vertical
23. Linearity of directional gestures
23
1.00
0.95
0.90
EAST
NORTH EAST
NORTH
NORTH WEST
WEST
SOUTH WEST
SOUTH
SOUTH EAST
24. Linearity of directional gestures
24
1.00
0.95
0.90
EAST
NORTH EAST
NORTH
NORTH WEST
WEST
SOUTH WEST
SOUTH
SOUTH EAST
Extension
Flexion
25. Mean directional biases of gestures
25
0
45
90
135
180
225
270
315
EAST
SOUTH EAST
SOUTH
SOUTH WEST
WEST
NORTH WEST
NORTH
NORTH EAST
26. Design recommendations
• Favor directional gestures when possible
!
• Provide to users means to select up/down
direction preferences
!
• Favor rotation invariant symbols for complex
gestures
!
• Gesture design should take into account
efforts to move the arm
26