Typing Performance of Blind Users: An Analysis of Touch Behaviors, Learning, and In-Situ Usage

TYPING PERFORMANCE OF

BLIND USERS HUGO NICOLAU

KYLE MONTAGUETIAGO GUERREIRO

ANDRÉ RODRIGUESVICKI L. HANSON

accessibility :: explore by touch

“Messages. Double-tap to open”

text-entry :: explore by touch

previous :: alternative techniques

Bonner et al., 2010

Azenkot et al., 2012

Oliveira et al., 2011

Southern et al., 2012

Yfantidis et al., 2006

Guerreiro et al., 2015

problem:: lack of understanding

Words per Minute

Error Rate

problem:: how to improve?

?

??

?

contribution :: new knowledge

contribution :: how? why?1 2 3 4 5 6 7 8

1.6 4.0Wor

ds p

er M

inut

e

contribution :: longitudinal study

8

weeks

participants:: novice

5users

apparatus :: S3 mini

procedure :: weekly assessment

week week week week week week week week

20-minute typing tasks

apparatus :: in-situ usage

TinyBlackBoxSupporting Mobile In-The-Wild Studies

results

words per minutehow?

performance :: words per minute

1 2 3 4 5 6 7 81

2

3

4

5

P2P4P1P3P5

Wor

ds p

er M

inut

e

performance :: words per minute

1 2 3 4 5 6 7 81

2

3

4

5

P2P4P1P3P5

Wor

ds p

er M

inut

e

performance :: words per minute

1 2 3 4 5 6 7 81

2

3

4

5

P2P4P1P3P5

Wor

ds p

er M

inut

e

performance :: words per minute

1 2 3 4 5 6 7 81

2

3

4

5

P2P4P1P3P5

Wor

ds p

er M

inut

e

words per minutewhy?

wpm :: land-on accuracy

27% (SD=12)

48% (SD=15)

week 1 week 8

wpm :: movement efficiency

P1 Week 1 P1 Week 8

wpm :: less re-entries

1 2 3 4 5 6 7 8

6.60.8

week

error rateshow?

performance :: total error rate

1 2 3 4 5 6 7 80%

10%

20%

30%

40%

50%P1P2P3P4P5

performance :: uncorrected error rate

1 2 3 4 5 6 7 80%

5%

10%

15%

20%

25%P1P2P3P4P5

performance :: corrected error rate

3 out of 10deleted characters

were correct

performance :: correction time

1 2 3 4 5 6 7 8

32 13Corr

ectio

n Ti

me

(%)

types of errors :: performance

1 2 3 4 5 6 7 80%

5%

10%

15%

20%

25% SubstitutionsOmissionsInsertions

substitutionswhy?

types of errors :: slips

38%

types of errors :: feedback delay

64%

substitutions :: key not visited

36%

major results

summary :: major results

Improve performance at slow rate Due to several factorsSubstitutions are predominantCorrect most errors Corrections are time consuming

summary :: major results

Improve performance at slow rate Due to several factorsSubstitutions are predominantCorrect most errors Corrections are time consuming

summary :: major results

Improve performance at slow rate Due to several factorsSubstitutions are predominantCorrect most errors Corrections are time consuming

summary :: major results

Improve performance at slow rate Due to several factorsSubstitutions are predominantCorrect most errors Corrections are time consuming

summary :: major results

Improve performance at slow rate Due to several factorsSubstitutions are predominantCorrect most errors Corrections are time consuming

implications

correction :: easier and efficient

synchronization :: output and input

“H”“B”

“N”

“M”

touch models :: leverage movement

HUGO NICOLAUhttp://web.ist.utl.pt/hugo.nicolau

TYPING PERFORMANCE OF BLIND USERS

SOS