Elderly Text-EntryPerformance onTouchscreensHugo Nicolauhman@vimmi.inesc-id.ptJoaquim Jorge
Mobile evolution
… led us to touchscreens
Direct Manipulation
Engaging
Adaptable[Findlater et al., 2012]
Hard to select targets[Jin et al., 2007]
Occurs to everyone[Nicolau, 2012]
Elderly
Hand tremor[Strickland and Bertoni, 2004]
Small targets    [Jin et al., 2007]
Text-Entry is a challenge
Transversal task   Communication    Document          Note                    editing           takingTextInput           ...
Re-visiting adaptability
Provide the knowledge
User Study
Text-Entry Performance
Hand tremor
ApparatusTablet:20x10 mmMobile:10x10 mm
Participants15 participants (4 males)67 to 89 years oldRight-handedNo severe visual impairmentsNo familiarity with touchde...
Two Phases1st   - Familiarization2nd - Evaluation
FamiliarizationExplanation and exemplificationCopy tasks30 minute practice session
Physiological tremor assessmentAction tremor (task-specific)Archimedes Spiral [Bain et al., 1993]Postural tremorAccelerome...
Copy Task1 practice sentences / condition5 test sentences / conditionPortuguese languagerepresentative corpusError correct...
Dependent MeasuresSpeed:Words per minuteAccuracy:Minimum String Distance error rateSubstitution error rateInsertion error ...
Results
Tremor ProfileTask-specific TremorArchimedes Spiral DrawingsPostural TremorHand Oscillation[Oulasvirta et al., 2011]Peak M...
Tremor ProfileTask-specific TremorArchimedes Spiral DrawingsPostural TremorHand Oscillation[Oulasvirta et al., 2011]Peak M...
Text-Entry Performance
Error RateMinimum String Distance (MSD) Error Rate       26%                     17%        Mobile                 Tablet
Tablet Compensates ErrorsMinimum String Distance (MSD) Error Rate          Statistically Significant          [Z=-2.417, p...
Correlation with Hand OscillationMinimum String Distance (MSD) Error RateHand OscillationNon-dominant handY [Pearson r=.75...
Types of ErrorsError Rate 6%      8%      13%         4%      4%      9%        Mobile                      Tablet       I...
Omissions
Omission were the most commonError Rate 6%      8%      13%         4%      4%      9%        Mobile                      ...
Omission were the most commonError Rate                     No Significant Difference                     [Z=-.722, p>.4] ...
Blank space was recurrently omittedOmission Error Rate in Mobile condition  28%                 23%                       ...
Forgetfulness and coordination arereal issues#13 Usually forgot to transcribe words atmiddle and end of sentences#8 “where...
Unintentional touches
Insertions
Insertion Error Rate 6%     8%      13%         4%      4%      9%       Mobile                      Tablet      Insertion...
Few Insertions with TabletError Rate    Statistically Significant    [Z=-2.103, p<.05] 6%      8%      13%         4%     ...
Bounces and Accidental TouchesError Rate      1.5%      3.3%        2.2%        1.1%             Mobile              Table...
Few Accidental Touches with TabletError Rate            Statistically Significant                      [Z=-2.292, p<.05]  ...
Correlations with Hand TremorError RateDominant Hand OscillationX [Spearman rho=.596, n=14, p<.05]                    Non-...
Deal with Insertion ErrorsRequired:      r e c e i t a d o (English: prescribed)Transcribed:   rreceiittadoo
Substitutions
Substitution Error Rate 6%     8%      13%         4%      4%      9%       Mobile                      Tablet      Insert...
Few Substitutions with TabletError Rate             Statistically Significant             [Z=-2.731, p<.01] 6%      8%    ...
Correlation with task-specific tremor Error Rate[Spearman rho=.624, n=15, p<.05][Spearman rho=.541, n=9, p<.05]           ...
Substitution PatternsMobile Error Rate
Right-Bottom Substitution PatternLift Points – Mobile condition
Similar and Symmetrical Substitutionsp -> qi -> j , i -> lParticipant #11:   m -> w , n -> uCognitive errors?
Most Substitutions are due to Poor AimingError Rate     1.1%    6.7%              0.2%    3.5%         Mobile             ...
Most Substitutions are due to Poor AimingError Rate                                  Statistically Significant Statistical...
Preferences   andComments
Participants Preference        2         13      Mobile      Tablet
Participants Comments“I am always hitting neighboring keys”“The hardest thing is trying not to tremblewhile typing”“The ma...
InclusiveKeyboards
Implications
ImplicationsShift keyboard layout
ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviors
ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger slips
ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger sli...
ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger sli...
ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger sli...
ConclusionElderly Text-Entry PerformanceEmpirical Body of KnowledgeError PatternsDesign Implications
Future WorkAnalyze hand tremor dataDevelop touch modelsCompensate input errors         Touch                              ...
The End.Hugo Nicolauhman@vimmi.inesc-id.pthttp://web.ist.utl.pt/hugo.nicolau/
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Elderly Text-Entry Performance on Touchscreens

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Elderly Text-Entry Performance on Touchscreens

  1. 1. Elderly Text-EntryPerformance onTouchscreensHugo Nicolauhman@vimmi.inesc-id.ptJoaquim Jorge
  2. 2. Mobile evolution
  3. 3. … led us to touchscreens
  4. 4. Direct Manipulation
  5. 5. Engaging
  6. 6. Adaptable[Findlater et al., 2012]
  7. 7. Hard to select targets[Jin et al., 2007]
  8. 8. Occurs to everyone[Nicolau, 2012]
  9. 9. Elderly
  10. 10. Hand tremor[Strickland and Bertoni, 2004]
  11. 11. Small targets [Jin et al., 2007]
  12. 12. Text-Entry is a challenge
  13. 13. Transversal task Communication Document Note editing takingTextInput Managing Web contacts browsing
  14. 14. Re-visiting adaptability
  15. 15. Provide the knowledge
  16. 16. User Study
  17. 17. Text-Entry Performance
  18. 18. Hand tremor
  19. 19. ApparatusTablet:20x10 mmMobile:10x10 mm
  20. 20. Participants15 participants (4 males)67 to 89 years oldRight-handedNo severe visual impairmentsNo familiarity with touchdevices
  21. 21. Two Phases1st - Familiarization2nd - Evaluation
  22. 22. FamiliarizationExplanation and exemplificationCopy tasks30 minute practice session
  23. 23. Physiological tremor assessmentAction tremor (task-specific)Archimedes Spiral [Bain et al., 1993]Postural tremorAccelerometer data [Selker et al., 2011]
  24. 24. Copy Task1 practice sentences / condition5 test sentences / conditionPortuguese languagerepresentative corpusError correction was notavailable
  25. 25. Dependent MeasuresSpeed:Words per minuteAccuracy:Minimum String Distance error rateSubstitution error rateInsertion error rateOmission error rate
  26. 26. Results
  27. 27. Tremor ProfileTask-specific TremorArchimedes Spiral DrawingsPostural TremorHand Oscillation[Oulasvirta et al., 2011]Peak Magnitude[Salarian et al., 2007][Elble and Koller, 1990]
  28. 28. Tremor ProfileTask-specific TremorArchimedes Spiral DrawingsPostural TremorHand Oscillation[Oulasvirta et al., 2011]Peak Magnitude[Salarian et al., 2007][Elble and Koller, 1990]
  29. 29. Text-Entry Performance
  30. 30. Error RateMinimum String Distance (MSD) Error Rate 26% 17% Mobile Tablet
  31. 31. Tablet Compensates ErrorsMinimum String Distance (MSD) Error Rate Statistically Significant [Z=-2.417, p<.05] 26% 17% Mobile Tablet
  32. 32. Correlation with Hand OscillationMinimum String Distance (MSD) Error RateHand OscillationNon-dominant handY [Pearson r=.751, n=9, p<.05]Z [Pearson r=.613, n=9, p=.079] 26% 17% Mobile Tablet
  33. 33. Types of ErrorsError Rate 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  34. 34. Omissions
  35. 35. Omission were the most commonError Rate 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  36. 36. Omission were the most commonError Rate No Significant Difference [Z=-.722, p>.4] 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  37. 37. Blank space was recurrently omittedOmission Error Rate in Mobile condition 28% 23% 16% 15% e i v x m p u zSPACE s w o r k n q y c t d f g h j a b l
  38. 38. Forgetfulness and coordination arereal issues#13 Usually forgot to transcribe words atmiddle and end of sentences#8 “where was I?”
  39. 39. Unintentional touches
  40. 40. Insertions
  41. 41. Insertion Error Rate 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  42. 42. Few Insertions with TabletError Rate Statistically Significant [Z=-2.103, p<.05] 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  43. 43. Bounces and Accidental TouchesError Rate 1.5% 3.3% 2.2% 1.1% Mobile Tablet Bounces Accidental
  44. 44. Few Accidental Touches with TabletError Rate Statistically Significant [Z=-2.292, p<.05] 1.5% 3.3% 2.2% 1.1% Mobile Tablet Bounces Accidental
  45. 45. Correlations with Hand TremorError RateDominant Hand OscillationX [Spearman rho=.596, n=14, p<.05] Non-Dominant Hand Oscillation Y [Spearman rho=.762, n=9, p<.05] 1.5% 3.3% 2.2% 1.1% Mobile Tablet Bounces Accidental
  46. 46. Deal with Insertion ErrorsRequired: r e c e i t a d o (English: prescribed)Transcribed: rreceiittadoo
  47. 47. Substitutions
  48. 48. Substitution Error Rate 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  49. 49. Few Substitutions with TabletError Rate Statistically Significant [Z=-2.731, p<.01] 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  50. 50. Correlation with task-specific tremor Error Rate[Spearman rho=.624, n=15, p<.05][Spearman rho=.541, n=9, p<.05] [Spearman rho=.539, n=15, p<.05] 6% 8% 13% 4% 4% 9% Mobile Tablet Insertions Substitutions Omissions
  51. 51. Substitution PatternsMobile Error Rate
  52. 52. Right-Bottom Substitution PatternLift Points – Mobile condition
  53. 53. Similar and Symmetrical Substitutionsp -> qi -> j , i -> lParticipant #11: m -> w , n -> uCognitive errors?
  54. 54. Most Substitutions are due to Poor AimingError Rate 1.1% 6.7% 0.2% 3.5% Mobile Tablet Slip Poor Aiming
  55. 55. Most Substitutions are due to Poor AimingError Rate Statistically Significant Statistically Significant [Z=-2.944, p<.01] [Z=-3.107, p<.01] 1.1% 6.7% 0.2% 3.5% Mobile Tablet Slip Poor Aiming
  56. 56. Preferences andComments
  57. 57. Participants Preference 2 13 Mobile Tablet
  58. 58. Participants Comments“I am always hitting neighboring keys”“The hardest thing is trying not to tremblewhile typing”“The main difficulty for me is in knowingwhere the letters are. I am not used to it(the keyboard)”
  59. 59. InclusiveKeyboards
  60. 60. Implications
  61. 61. ImplicationsShift keyboard layout
  62. 62. ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviors
  63. 63. ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger slips
  64. 64. ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger slipsUse language-based correctors
  65. 65. ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger slipsUse language-based correctorsAllow personalization
  66. 66. ImplicationsShift keyboard layoutAvoid errors by understanding typingbehaviorsDeal with poor aiming rather than finger slipsUse language-based correctorsAllow personalizationCompensate hand tremor
  67. 67. ConclusionElderly Text-Entry PerformanceEmpirical Body of KnowledgeError PatternsDesign Implications
  68. 68. Future WorkAnalyze hand tremor dataDevelop touch modelsCompensate input errors Touch + Intended key Accelerometer data
  69. 69. The End.Hugo Nicolauhman@vimmi.inesc-id.pthttp://web.ist.utl.pt/hugo.nicolau/

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