1. Towards Mobile Touch Screen
Inclusive User Interfaces:
Differences and Similarities between
Motor Impaired and Able-Bodied Users
Hugo Nicolau
Tiago Guerreiro
Daniel Gonçalves
Joaquim Jorge

2. Mobile
evolution

5. Tactile feedback
loss of tactile
feedback

6. Loss of physical stability

7. hard to select targets

8. it occurs to everyone

9. … and motor
impaired

10. some advantages

11. more pleasant

12. require less strength

13. Adapt to users’ needs

16. Provide the knowledge to
build better touch interfaces

17. We performed …

18. Tested several …
Interaction
Techniques

19. Screen areas …
… edges

20. Screen areas …
… middle

21. Screen areas …
5
4
3
2
1
… vertical distance

22. … and target sizes
7 mm 12 mm 17 mm

23. Tapping

24. Crossing

25. Directional Gesturing

26. 15 participants
28-64 years old
C4-C7 lesion level
6 left-handed
never used touchscreens

27. 18 participants
5 females, 13 males
20-45 years old

28. Results

29. Error Rate
X

30. Target
Size

31. Motor Impaired
50%
40%
30%
20%
10%
0%
7mm 12mm 17mm
Gestures Tapping Crossing

32. Able-bodied
25%
20%
15%
10%
5%
0%
7mm 12mm 17mm
Gestures Tapping Crossing

33. Differences and Similarities
Tapping is the most similar
Magnitude of errors
Directional Gesturing

34. Middle

35. Motor Impaired
50%
40%
30%
20%
10%
0%
7mm 12mm 17mm
Gestures4Way Tapping Middle Crossing

36. Able-bodied
14%
12%
10%
8%
6%
4%
2%
0%
7mm 12mm 17mm
Gestures Middle Tapping Middle Crossing

37. Differences and Similarities
Similar performances with
all techniques
Differences are in the
remaining of the screen

38. Edges

39. Motor Impaired
60%
40%
20%
0%
7mm 12mm 17mm
Tapping Middle Tapping Edge
60%
40%
20%
0%
Gesture Edge Gesture Middle

40. Able-bodied
30%
25%
20%
15%
10%
5%
0%
7mm 12mm 17mm
Tapping Middle Tapping Edge

41. Differences and Similarities
Edges do not provide
additional support
Tapping is hindered on edges

42. Vertical
Distance

43. Motor Impaired
48% 31% 27%
43% 25% 28%
39% 28% 24%
40% 19% 15%
47% 19% 9%
7mm 12mm 17mm
Tapping

44. Able-bodied
10% 0% 0%
6% 2% 0%
8% 0% 0%
8% 1% 0%
38% 6% 0%
7mm 12mm 17mm
Tapping

45. Differences and Similarities
Tapping small targets,
particularly near lower edge
Reach restrictions

46. Towards
Inclusive
Design

47. Tapping is a suitable interaction
technique
The one with more
resemblances
Lowest error rates
12mm as a good compromise

48. Magnitude of errors
Much higher for motor
impaired 40%
35%
30%
25%
20% 26x 5.6x 6x
15%
10%
5%
0%
Gestures Tapping Crossing

49. Able-bodied can easily perform
Directional Gestures
Suitable alternative to Tapping
(small targets)
Motor impaired have many
difficulties

50. Middle of the screen consistency
Similar performance with all
interaction techniques
Remaining of the screen can
hinder or favor interaction

51. Reach restrictions
Upper edge targets are
harder to acquire for M.I.
For A.B. small targets near
bottom edge are harder

52. Future Work
Instantiate our findings
Investigate situational
impairments

53. THE END.
Hugo Nicolau
hman@vimmi.inesc-id.pt