"Blind People and Mobile Touch-based Text-Entry: Acknowledging the Need for Different Flavors" @ ASSETS 2011
•
2 likes•1,558 views
My presentation at ASSETS 2011, in Dundee Scotland. We won the Best StudentPaper Award. Abstract: The emergence of touch-based mobile devices brought fresh and exciting possibilities. These came at the cost of a considerable number of novel challenges. They are particularly apparent with the blind population, as these devices lack tactile cues and are extremely visually demanding. Existing solutions resort to assistive screen reading software to compensate the lack of sight, still not all the information reaches the blind user. Good spatial ability is still required to have notion of the device and its interface, as well as the need to memorize buttons‟ position on screen. These abilities, as many other individual attributes as age, age of blindness onset or tactile sensibility are often forgotten, as the blind population is presented with the same methods ignoring capabilities and needs. Herein, we present a study with 13 blind people consisting of a touch screen text-entry task with four different methods. Results show that different capability levels have significant impact on performance and that this impact is related with the different methods‟ demands. These variances acknowledge the need of accounting for individual characteristics and giving space for difference, towards inclusive design. http://www.youtube.com/watch?v=p9JMtC3SMhA
Recommended
Recommended
More Related Content
Recently uploaded
Recently uploaded (20)
Featured
Featured (20)
"Blind People and Mobile Touch-based Text-Entry: Acknowledging the Need for Different Flavors" @ ASSETS 2011
- 1. Blind People and Mobile Touch-based Text-Entry Acknowledging the Need for Different Flavors Tiago Guerreiro tjvg@vimmi.inesc-id.pt
- 3. ‘‘ If we cannot now end our differences, at least we can help make ’’ the world safe for diversity — John Fitzgerald Kennedy
- 17. Difficult to select targets
- 18. Loss of physical stability
- 21. Match individual characteristics with interface demands
- 41. 15 blind users
- 42. 24 to 68 years old
- 43. All but two text regularly
- 44. Only one had previous experience with touch screens mobiles
- 48. One session per method 4 Methods
- 50. 97% correlation
- 52. Practice phase 10 to 15 minutes 2 users were not able to write with QWERTY and MultiTap
- 54. Words per Minute
- 55. 2.5 2.0 1.5 1.0 0.5 0.0 QWERTY MultiTap NavTouch BrailleType
- 56. MSD Error Rate
- 57. 25.0 20.0 15.0 10.0 5.0 0.0 QWERTY MultiTap NavTouch BrailleType
- 58. 25.0 20.0 15.0 10.0 5.0 0.0 QWERTY MultiTap NavTouch BrailleType
- 60. Easy to Method understand QWERTY 4.0 (2) MultiTap 4.0 (2) NavTouch 5.0 (1) BrailleType 5.0 (1)
- 61. Easy to Easy Method understand to use QWERTY 4.0 (2) 4.0 (2) MultiTap 4.0 (2) 4.0 (1) NavTouch 5.0 (1) 4.5 (2) BrailleType 5.0 (1) 5.0 (1)
- 62. Allows to Easy to Easy Method input text understand to use quickly QWERTY 4.0 (2) 4.0 (2) 4.0 (3) MultiTap 4.0 (2) 4.0 (1) 3.5 (2) NavTouch 5.0 (1) 4.5 (2) 3.0 (3) BrailleType 5.0 (1) 5.0 (1) 3.0 (1)
- 63. Allows to I would Easy to Easy Method input text use this understand to use quickly method QWERTY 4.0 (2) 4.0 (2) 4.0 (3) 3.0 (3) MultiTap 4.0 (2) 4.0 (1) 3.5 (2) 4.0 (3) NavTouch 5.0 (1) 4.5 (2) 3.0 (3) 3.0 (1) BrailleType 5.0 (1) 5.0 (1) 3.0 (1) 3.5 (1)
- 65. Method Main Difficulties Targets too close and small QWERTY Split-tapping edge targets.
- 66. Method Main Difficulties Targets too close and small QWERTY Split-tapping edge targets. MultiTap Multiple split-tapping
- 67. Method Main Difficulties Targets too close and small QWERTY Split-tapping edge targets. MultiTap Multiple split-tapping Involuntary touches NavTouch Losing track of text
- 68. Method Main Difficulties Targets too close and small QWERTY Split-tapping edge targets. MultiTap Multiple split-tapping Involuntary touches NavTouch Losing track of text Timeouts BrailleType Losing track of text
- 70. BrailleType
- 71. BrailleType
- 72. BrailleType
- 77. Allow faster writing. More complex and erroneous.
- 79. Large number of targets is highly demanding. Users with better spatial abilities are able to overcome this demand.
- 80. More demanding in regards to Memory and Atention. Users with better Verbal IQ are able to overcome this demand.
- 81. Different method, different demands. Different users, diverse abilities.
- 82. Spatial ability, pressure sensitivity and verbal IQ play an important role in the blind user’s ability to use a touch screen.
- 83. The Future Different devices Low-level demands Long term studies
- 85. Tiago Guerreiro João Oliveira Hugo Nicolau Joaquim Jorge Daniel Gonçalves
Editor's Notes
- Good morning everyone! My name is Tiago and I come from Portugal.
- My co-authors are João Oliveira, Daniel Gonçalves, Joaquim Jorge and….Hugo Nicolau who is also here. He is the one with the girly hair band!
- As JFK once said:If we cannot now end our differences, at least we can help make the world safe for diversityOur paper is about Individual Differences among blind people and how they are revealed when faced with different interface demands.
- So, we all acknowledge the power and benefits of mobile devices: they are great.
- And going straight to our focus group, blind people are now able to use mobile devices efficiently.
- Well not everyone….some better than others and some dramatically are not able to do so
- The population is diverse and in the absence of vision other senses and abilities are required…
- This happens with tact. And for example, a reasonable part of population acquires blindness in a late stage in life when tactile sensitivity is not the best. Further, blind people with diabetes may also experience a loss of sensitivity in their fingers.
- Or even, the moment in life where a person loses sight is likely to produce different spatial abilities so different ways to create a mental idea of space and relations between objects.
- Or even age and memory.
- So there are several individual differences among the population.
- And this diversity matters as in the absence of vision these abilities are stressed and the users depend on them way more deeply than a sighted person.
- These differences in individual abilities have na impact in the way the users deal with technology
- And in particular with more demanding devices. In this paper we focus on touch screens.
- But also a lot of challenges
- Our goal here
- Was to assert the relation between some abilities and demands and try to match them to foster more inclusive design
- All solutions using voice feedback …
- Fifteen blind users
- With ages between twenty four and sixty eight. We covered a large spectrum of the blind population, between early and late blind users.
- All but two texted frequently
- All knew the braille alphabet (some experienced and some with low reading and writing abilities)
- Two never learned to use a computer
- Look, I got a dot. Lem me breath. Learning from the best!
- The text-entry part of our study was composed of 4 sessions with each user, one per method.
- Duringthetesterasewasunavailable as wewanted to seethequalityofthetranscribedtextwithoutcorrections
- Regarding the methods and particularly input speed we looked at Words per Minute
- And we found significant differences between both QWERTY and MULTITAP and NAvTouch and BrailleType.
- Regarding accuracy, so the similarity between the desired and transcribed sentences we used Minimum String Distance Error Rate.
- And Braille Type showed to be less erroneous than the faster methods
- While NavTouch showed to be less erroneous than MultiTap
- As to a method being Easy to Understand NavTouch and BrailleType showed to be easier than the remaining 2
- And they were also considered easier to use
- And as expected the faster methods were considered as such by the participants
- Surprinsigly, users said they would use MultiTap or BrailleType, some because they wanted a fast method, some because they wanted a simpler one.
- In our observation we also looked at the most prominent barriers and difficulties
- Regarding QWERTY most of the problems arise from the number and size of the targets: they are too close and small and that turns the task demanding for a novice user. Further the users were not used to composed gestures like spliut-tapping and had problems particularly near the edges.
- Following this idea, most on the errors with MultiTap arose from multi split-tapping
- As to NavTouch the users did several involuntary touches and as each selection is lengthy sometimes they would lose track of text
- BrailleType had issues with the timeout we applied (timeouts are hazardous) and users also did lose track of text sometimes
- Looking at individual abilities and how they relate with different device demands…
- We saw that people with lower verbal IQ (memory and attention), performed worse in all methods but this only happens until a particular level showing that the methods’ demands are surpassed after a certain ability threshold.
- As to Spatial Ability, differences were found between users with different abilities at QWERTY and MultiTap so users with the best spatial abilities performed better at these methods than the others. This does not happen with NavTouch and BrailleType
- Another individual feature that showed relevance was pressure sensitivity, a measure of tactile sensitivity, in methods where split-tapping was used. It is visible at MultiTap.
- As to more functional abilities:
- No relation was found between the proficiency using a physical keyboard and QWERTY
- Nor between using a keypad MultiTap and the touch screen version of it
- We found an impact on the level of Braille reading proficiency and using BrailleType.
- Squeezing it all up, methods with several targets, fixed layout and scanning techniques allow for faster writing but they are more complex and erroneous
- While NavTouch and BrailleType are simples and less erroneous