U BI B RAILLE

Designing and Evaluating a Vibrotactile
Braille-Reading Device
HUGO	
  NICOLAU	
  
JOÃO	
  GUERREIRO	
  
TI...
motivation :: constantly online
blind users :: auditory feedback
challenge ::
alternative modality
problem :: deaf-blind users
problem :: mobile usage
problem :: noisy environments
problem :: privacy
earphones?
goal :: inconspicuous and private
[Al-Qudah et al, 2011]

[Jayant et al, 2010]

[Ohtsuka et al, 2008]

[Rantala et al, 2009]

related work
our approach :: UbiBraille
inspiration :: perkins brailler
example :: ‘a’
example :: ‘b’
same approach for reading
Six rings
Lilypad vibe board
Vibration motor (10 mm), 3,8 Volts
Arduino Mega ADK board

ubibraille :: hardware
ubibraille :: ‘b’
advantage :: mnemonic
advantage :: speed
1.

Will participants be able to
discriminate simultaneous
stimuli?
2.

Will participants be
able to leverage
Braille knowledge?
3.

What are the most
common error
patterns?
11 blind participants (8 male, 3 female)
Ages 21 – 61 (m=45, sd=16)
Braille typists

user study :: character recognition
assessment :: braille proficiency
user study :: procedure
26 letters x 2 blocks

1. Audio signal
2. Delay (2 seconds)
3. Random braille character (from 26 letters)
4. Answer
5. Mon...
results ::
character recognition
82%

60%
50%
40%

sd=17.25%

30%
20%
10%

overall accuracy

0%

a b c d e

f

g h

i

j

k

l

m n o p q

r

s

t

u

v w ...
error rate per character

60%
50%
40%
30%
20%
10%
0%
a b c d e

f

g h

i

j

k

l

m n o p q

r

s

t

u

v w x

y

z
‘novyz’ are harder

60%

55%

50%
40%

36%
32% 32%

32%

30%
20%
10%
0%
a b c d e

f

g h

i

j

k

l

m n o p q

r

s

t
...
‘novyz’ are harder

N

O

V

Y

Z

60%

55%

50%
40%

36%
32% 32%

32%

30%
20%
10%
0%
a b c d e

f

g h

i

j

k

l

m n ...
51.6%
error pattern :: 1 finger issues
N

O

Q

R

V

1 finger error :: insertion

Y

Z
N

O

V

Y

Z

Q

R

U

X

U

1 finger error :: omission
25.3%
error pattern :: 2 finger issues
Z

X

25.3%
error pattern :: 2 finger issues
accuracy rate per participant
100%
80%
60%
40%
20%
0%
P1

P2

P3

P4

P5

P6

P7

P8

P9

P10

P11
result :: individual differences
100%
80%
60%
40%
20%
0%
P1

P2

P3

P4

P5

P6

P7

P8

P9

P10

P11
[rho=.571, p=.066, N=11]

leverage braille knowledge :: reading
[rho=.627, p=.039, N=11]

leverage braille knowledge :: writing
Memory
82% overall accuracy
More fingers, more errors
Mostly 1-finger errors
Leverage braille knowledge

character recognition :: m...
user study #2 ::
word recognition
7 blind participants
(from study #1)

Ages 21 – 62

user study :: participants
1. Audio signal

2 times

2. Delay (2 seconds)
3. Random word
4. Answer
5. Monitor register answer

user study :: procedur...
‘a’

‘c’

stimulus

‘t’

interval

Condition

Stimulus (ms) Interval (ms)

4000ms

2000

2000

2000ms

1000

1000

1000ms
...
4 conditions (randomized)
10 words per condition
280 trials
5 characters per word
Commonly used words (Portuguese)

user s...
results ::
word recognition
recognition accuracy rate
100%
80%
60%
40%
20%
0%

93%

89%

64%

33%

4000ms

2000ms

1000ms

500ms

Error bars denote 95...
recognition accuracy rate
No sig. diff. p>.05
100%
80%
60%
40%
20%
0%

93%

89%

64%

33%

4000ms

2000ms

1000ms

500ms

E...
recognition accuracy rate
Z=-2.041, p<.05
100%
80%
60%
40%
20%
0%

93%

89%

64%

33%

4000ms

2000ms

1000ms

500ms

Erro...
recognition accuracy rate
Z=-2.379, p<.05
100%
80%
60%
40%
20%
0%

93%

89%

64%

33%

4000ms

2000ms

1000ms

500ms

Erro...
[rho=.805, p<.05, N=7]

[rho=.543, p=.208, N=7]

leverage braille knowledge ::
reading and writing
Identify through context
Condition
4000ms
2000ms
1000ms
500ms

Median
5
5
3
2

IQR
1
2
2
1

likert scale [1-5] : 5 is better

word recognition :: e...
Condition
4000ms
2000ms
1000ms
500ms

Median
5
5
3
2

IQR
1
2
2
1

likert scale [1-5] : 5 is better

longest durations are...
Condition
4000ms
2000ms
1000ms
500ms

Median
5
5
3
2

IQR
1
2
2
1

Z=-2.530, p<.05
Z=-2.428, p<.05

likert scale [1-5] : 5...
1s duration + 1s interval à 90%
leverage braille knowledge
12 wpm
room for improvements

word recognition :: major result...
conclusion ::
ubibraille
conclusion ::
inconspicuous communication
conclusion ::
leverage braille-related abilities
conclusion ::
character- and word-level results
future work ::
ubibraille
future work :: finger discrimination
future work :: new applications
future work ::
multi-point feedback
The End.
HUGO NICOLAU

hugonicolau@computing.dundee.ac.uk
paper and slides @ http:/
/web.ist.utl.pt/hugo.nicolau
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UbiBraille: Designing and Evaluating a Vibrotactile Braille-Reading Device.

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Research paper presented at SIGACCESS ASSETS 2013

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UbiBraille: Designing and Evaluating a Vibrotactile Braille-Reading Device.

  1. 1. U BI B RAILLE Designing and Evaluating a Vibrotactile Braille-Reading Device HUGO  NICOLAU   JOÃO  GUERREIRO   TIAGO  GUERREIRO   LUÍS  CARRIÇO  
  2. 2. motivation :: constantly online
  3. 3. blind users :: auditory feedback
  4. 4. challenge :: alternative modality
  5. 5. problem :: deaf-blind users
  6. 6. problem :: mobile usage
  7. 7. problem :: noisy environments
  8. 8. problem :: privacy
  9. 9. earphones?
  10. 10. goal :: inconspicuous and private
  11. 11. [Al-Qudah et al, 2011] [Jayant et al, 2010] [Ohtsuka et al, 2008] [Rantala et al, 2009] related work
  12. 12. our approach :: UbiBraille
  13. 13. inspiration :: perkins brailler
  14. 14. example :: ‘a’
  15. 15. example :: ‘b’
  16. 16. same approach for reading
  17. 17. Six rings Lilypad vibe board Vibration motor (10 mm), 3,8 Volts Arduino Mega ADK board ubibraille :: hardware
  18. 18. ubibraille :: ‘b’
  19. 19. advantage :: mnemonic
  20. 20. advantage :: speed
  21. 21. 1. Will participants be able to discriminate simultaneous stimuli?
  22. 22. 2. Will participants be able to leverage Braille knowledge?
  23. 23. 3. What are the most common error patterns?
  24. 24. 11 blind participants (8 male, 3 female) Ages 21 – 61 (m=45, sd=16) Braille typists user study :: character recognition
  25. 25. assessment :: braille proficiency
  26. 26. user study :: procedure
  27. 27. 26 letters x 2 blocks 1. Audio signal 2. Delay (2 seconds) 3. Random braille character (from 26 letters) 4. Answer 5. Monitor register answer user study :: procedure
  28. 28. results :: character recognition
  29. 29. 82% 60% 50% 40% sd=17.25% 30% 20% 10% overall accuracy 0% a b c d e f g h i j k l m n o p q r s t u v w x y z
  30. 30. error rate per character 60% 50% 40% 30% 20% 10% 0% a b c d e f g h i j k l m n o p q r s t u v w x y z
  31. 31. ‘novyz’ are harder 60% 55% 50% 40% 36% 32% 32% 32% 30% 20% 10% 0% a b c d e f g h i j k l m n o p q r s t u v w x y z
  32. 32. ‘novyz’ are harder N O V Y Z 60% 55% 50% 40% 36% 32% 32% 32% 30% 20% 10% 0% a b c d e f g h i j k l m n o p q r s t u v w x y z
  33. 33. 51.6% error pattern :: 1 finger issues
  34. 34. N O Q R V 1 finger error :: insertion Y Z
  35. 35. N O V Y Z Q R U X U 1 finger error :: omission
  36. 36. 25.3% error pattern :: 2 finger issues
  37. 37. Z X 25.3% error pattern :: 2 finger issues
  38. 38. accuracy rate per participant 100% 80% 60% 40% 20% 0% P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11
  39. 39. result :: individual differences 100% 80% 60% 40% 20% 0% P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11
  40. 40. [rho=.571, p=.066, N=11] leverage braille knowledge :: reading
  41. 41. [rho=.627, p=.039, N=11] leverage braille knowledge :: writing
  42. 42. Memory
  43. 43. 82% overall accuracy More fingers, more errors Mostly 1-finger errors Leverage braille knowledge character recognition :: major results
  44. 44. user study #2 :: word recognition
  45. 45. 7 blind participants (from study #1) Ages 21 – 62 user study :: participants
  46. 46. 1. Audio signal 2 times 2. Delay (2 seconds) 3. Random word 4. Answer 5. Monitor register answer user study :: procedure
  47. 47. ‘a’ ‘c’ stimulus ‘t’ interval Condition Stimulus (ms) Interval (ms) 4000ms 2000 2000 2000ms 1000 1000 1000ms 500 500 500ms 250 250 user study :: conditions ‘o’ ‘r’
  48. 48. 4 conditions (randomized) 10 words per condition 280 trials 5 characters per word Commonly used words (Portuguese) user study :: design
  49. 49. results :: word recognition
  50. 50. recognition accuracy rate 100% 80% 60% 40% 20% 0% 93% 89% 64% 33% 4000ms 2000ms 1000ms 500ms Error bars denote 95% CI
  51. 51. recognition accuracy rate No sig. diff. p>.05 100% 80% 60% 40% 20% 0% 93% 89% 64% 33% 4000ms 2000ms 1000ms 500ms Error bars denote 95% CI
  52. 52. recognition accuracy rate Z=-2.041, p<.05 100% 80% 60% 40% 20% 0% 93% 89% 64% 33% 4000ms 2000ms 1000ms 500ms Error bars denote 95% CI
  53. 53. recognition accuracy rate Z=-2.379, p<.05 100% 80% 60% 40% 20% 0% 93% 89% 64% 33% 4000ms 2000ms 1000ms 500ms Error bars denote 95% CI
  54. 54. [rho=.805, p<.05, N=7] [rho=.543, p=.208, N=7] leverage braille knowledge :: reading and writing
  55. 55. Identify through context
  56. 56. Condition 4000ms 2000ms 1000ms 500ms Median 5 5 3 2 IQR 1 2 2 1 likert scale [1-5] : 5 is better word recognition :: ease of use
  57. 57. Condition 4000ms 2000ms 1000ms 500ms Median 5 5 3 2 IQR 1 2 2 1 likert scale [1-5] : 5 is better longest durations are easier
  58. 58. Condition 4000ms 2000ms 1000ms 500ms Median 5 5 3 2 IQR 1 2 2 1 Z=-2.530, p<.05 Z=-2.428, p<.05 likert scale [1-5] : 5 is better longest durations are easier
  59. 59. 1s duration + 1s interval à 90% leverage braille knowledge 12 wpm room for improvements word recognition :: major results
  60. 60. conclusion :: ubibraille
  61. 61. conclusion :: inconspicuous communication
  62. 62. conclusion :: leverage braille-related abilities
  63. 63. conclusion :: character- and word-level results
  64. 64. future work :: ubibraille
  65. 65. future work :: finger discrimination
  66. 66. future work :: new applications
  67. 67. future work :: multi-point feedback
  68. 68. The End. HUGO NICOLAU hugonicolau@computing.dundee.ac.uk paper and slides @ http:/ /web.ist.utl.pt/hugo.nicolau

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