1 Chapter 4 Assistive Technology (AT) & User Interface

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Chapter 4Chapter 4

Assistive Technology (AT) &Assistive Technology (AT) &

User InterfaceUser Interface

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Assistive TechnologyAssistive Technology

Used by individuals with disabilities in order Used by individuals with disabilities in order to perform functions that might otherwise be to perform functions that might otherwise be difficult or impossible difficult or impossible

Devices used by people with disabilities to Devices used by people with disabilities to access computers.access computers.

Two types:Two types: devicedevice service service

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Assistive Technology: DeviceAssistive Technology: Device

Any item or piece of equipment used to Any item or piece of equipment used to maintain or improve the functional capabilities maintain or improve the functional capabilities of a person with a disability of a person with a disability

Many high-tech and low-tech devices are now Many high-tech and low-tech devices are now available to assist people with disabilities with available to assist people with disabilities with daily living tasks, communication, education, daily living tasks, communication, education, work, and recreation work, and recreation

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Example:Example: people with limited hand function may use a people with limited hand function may use a

keyboard with large keys or a special mouse to keyboard with large keys or a special mouse to operate a computer operate a computer

people who are blind may use software that reads people who are blind may use software that reads text on the screen in a computer-generated voice text on the screen in a computer-generated voice

people with low vision may use software that people with low vision may use software that enlarges screen content enlarges screen content

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Example: (cont…)Example: (cont…) people who are deaf may use a TTY (text people who are deaf may use a TTY (text

telephone)telephone) people with speech impairments may use a device people with speech impairments may use a device

that speaks out loud as they enter text via a that speaks out loud as they enter text via a keyboardkeyboard

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Assistive Technology: ServiceAssistive Technology: Service

Support people with disabilities or their Support people with disabilities or their caregivers to help them select, acquire, or use caregivers to help them select, acquire, or use AT devices.AT devices.

Such services also include functional Such services also include functional evaluations, training on or demonstration of evaluations, training on or demonstration of devices, and purchasing or leasing devices. devices, and purchasing or leasing devices.

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The Impact & Benefits of Assistive The Impact & Benefits of Assistive Technology Technology

Based on a preliminary study (National Based on a preliminary study (National Council on Disability , 1993) surveyed 136 Council on Disability , 1993) surveyed 136 individuals with disabilities:individuals with disabilities: majority of infants with disabilities benefited by majority of infants with disabilities benefited by

having fewer health problems having fewer health problems school age children were able to remain in a school age children were able to remain in a

regular classroom & reduce their use of school-regular classroom & reduce their use of school-related services related services

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The Impact & Benefits of Assistive The Impact & Benefits of Assistive TechnologyTechnology

Based on a preliminary study (National Based on a preliminary study (National Council on Disability , 1993) surveyed 136 Council on Disability , 1993) surveyed 136 individuals with disabilities: (cont…)individuals with disabilities: (cont…) working-age persons were able to:working-age persons were able to:

reduce dependence on family membersreduce dependence on family members reduce dependence on paid assistance reduce dependence on paid assistance increase earnings increase earnings

Elderly persons were able to:Elderly persons were able to: reduce dependence on othersreduce dependence on others reduce dependency on paid persons reduce dependency on paid persons avoid entering a nursing home avoid entering a nursing home

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Categories of Assistive Technology Categories of Assistive Technology

Aids for Daily Living:Aids for Daily Living: Self help aids for use in activities such as eating, Self help aids for use in activities such as eating,

bathing, cooking, dressing, toileting, home bathing, cooking, dressing, toileting, home maintenance, etc. maintenance, etc.

Augmentative or Alternative Communication Augmentative or Alternative Communication (AAC): (AAC): Electronic and non-electronic devices that provide Electronic and non-electronic devices that provide

a means for expressive and receptive a means for expressive and receptive communication for persons with limited or no communication for persons with limited or no speechspeech. .

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Computer Access:Computer Access: Input and output devices (voice, Braille), alternate Input and output devices (voice, Braille), alternate

access aids (headsticks, light pointers), modified or access aids (headsticks, light pointers), modified or alternate keyboards, switches, special software, alternate keyboards, switches, special software, etc. that enable persons with disabilities to use a etc. that enable persons with disabilities to use a computer. computer.

This category includes speech recognition This category includes speech recognition software. software.

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Environmental Control Systems:Environmental Control Systems: Primarily Primarily electronic systemselectronic systems that enable someone that enable someone

with limited mobility to with limited mobility to controlcontrol various appliances, various appliances, electronic aids, security systems, etc. in their room, electronic aids, security systems, etc. in their room, home or other home or other surroundingssurroundings. .

Home/Worksite Modifications:Home/Worksite Modifications: Structural adaptations, fabrications in the home, Structural adaptations, fabrications in the home,

worksite or other area (ramps, lifts, bathroom worksite or other area (ramps, lifts, bathroom changes) that changes) that remove or reduce physical barriersremove or reduce physical barriers for an individual with a disability. for an individual with a disability.

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Prosthetics and Orthotics:Prosthetics and Orthotics: Replacement, substitution or augmentation of Replacement, substitution or augmentation of

missing or malfunctioning body parts with missing or malfunctioning body parts with artificial limbs or other orthotic aids (splints, artificial limbs or other orthotic aids (splints, braces, etc.). braces, etc.).

There are also prosthetics to assist with cognitive There are also prosthetics to assist with cognitive limitations or deficits, including audio tapes or limitations or deficits, including audio tapes or pagers (that function as prompts or pagers (that function as prompts or remindersreminders). ).

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Seating and Positioning:Seating and Positioning: Accommodations to a wheelchair or other Accommodations to a wheelchair or other seating systemseating system

to provide greater body stability, trunk/head support and an to provide greater body stability, trunk/head support and an upright posture, and reduction of pressure on the skin upright posture, and reduction of pressure on the skin surface (cushions, contour seats, lumbar). surface (cushions, contour seats, lumbar).

Service Animals:Service Animals: any guide dog (for visually impaired and blind individuals), any guide dog (for visually impaired and blind individuals),

signal dog (for hearing impaired or Deaf individuals), or signal dog (for hearing impaired or Deaf individuals), or other animal individually trained to provide assistance to other animal individually trained to provide assistance to an individual with a disability. an individual with a disability.

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Aids for Vision Impaired:Aids for Vision Impaired: Aids for specific populations including magnifiers, Aids for specific populations including magnifiers,

Braille or speech output devices, large print Braille or speech output devices, large print screens, closed circuit television for magnifying screens, closed circuit television for magnifying documents, etc. documents, etc.

Aids for Hearing Impaired:Aids for Hearing Impaired: Aids for specific populations including assistive Aids for specific populations including assistive

listening devices (infrared, FM loop systems), listening devices (infrared, FM loop systems), hearing aids, TTYs, visual and tactile alerting hearing aids, TTYs, visual and tactile alerting systems, etc. systems, etc.

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Wheelchairs/Mobility Aids:Wheelchairs/Mobility Aids: Manual and electric wheelchairs, mobile bases for Manual and electric wheelchairs, mobile bases for

custom chairs, walkers, three-wheel scooters and custom chairs, walkers, three-wheel scooters and other utility vehicles for increasing personal other utility vehicles for increasing personal mobility. mobility.

Vehicle Modification:Vehicle Modification: Adaptive driving aids, hand controls, wheelchair Adaptive driving aids, hand controls, wheelchair

and other lifts, modified vans, or other motor and other lifts, modified vans, or other motor vehicles used for personal transportation. vehicles used for personal transportation.

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User Interface in Assistive User Interface in Assistive Technology Technology

AT requires different UI from ordinary AT requires different UI from ordinary technologies.technologies.

Tangible user interfaces (TUIs) are a favorable medium for the implementation of AT.

Two types of design related to AT design: Universal Inclusive

main differentiating factor is their means of increasing accessibility

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User Interface in Assistive User Interface in Assistive Technology: UniversalTechnology: Universal

Focusing on the usability of the technology Making it more accessible for all potential

users Strives to create designs which are usable by

the entire population, regardless of age, race, disability, gender, ability level, perceptions, values, and so on. Can’t be fully realized for certain user groups will

always require technology to be developed specifically for them

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User Interface in Assistive User Interface in Assistive Technology: Inclusive Technology: Inclusive

Focusing on the capabilities of the intended users

Building technologies that are accessible to them but not necessarily accessible or usable by other groups of users (Steinfeld, 1994).

This design defines AT better for it helps bridge the gap between user capabilities and the demands of mainstream technology

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User Interface in Assistive User Interface in Assistive Technology: Inclusive Technology: Inclusive

AT is not limited to augmenting mainstream technology for mainstream tasks

It can also help particular classes of impaired user engage in tasks specific to their impairment.

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Design and Technology

When a tool to carry out a task demands more capabilities from a user group than they possess, one of a four ways may solve the problem.

Four ways in which a user can go about simplifying the structure of a task (Norman, 1988):

a. keep the task much the same, but provide mental aidsb. use technology to make visible what would otherwise be

invisible, thus improving feedback and the ability to keep control

c. automate, but keep the task much the samed. change the nature of the task

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Design and Technology Design and Technology

Assistive technology could be used to augment one or more existing tools.

Falls under Inclusive design.

Skill demanded by tool

AT

User’s capabilities

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The usability of the tool could be increased through universal design

Reducing the skills demanded from the user.



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An assistive technology could automate the task, thus placing zero or minimal demand on the user

E.g.: a gas cooker that turns itself off after a set time.



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Inclusive design could be used to create a new set of tasks which didn’t exist previously

Subsume the tasks when needed to be simplified.

E.g.: adding a wheelchair ramp where there were stairs before, rather than building a stair-climbing wheelchair.


AT

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Design and TechnologyDesign and Technology

Many forms of AT user interfaces such as Many forms of AT user interfaces such as electronic and graphical display.electronic and graphical display.

Focus on Focus on Tangible UITangible UI for it can offer more for it can offer more than other AT UIs.than other AT UIs.

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Designing Tangible User Interfaces

Definition of TUI:Definition of TUI: system which gives physical form to digital

information and/or computational functions. There are two broad design philosophies as

stated earlier: Universal Universal tasks are rendered easier by making

technology more usable for all Inclusive tasks are made possible for certain

user groups by building assistive technologies for that user group

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Universal Design of Tangible User Interfaces

Seven defining principles of universal design (Connell et al., 1997):

1. Equitable Use2. Flexibility in Use3. Simple and Intuitive Use4. Perceptible Information5. Tolerance for Error6. Low Physical Effort7. Size and Space for Approach and Use

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1. Equitable Use: Hand-sized objects, which have a high contrast

with their environment, are likely to be useable by a greater proportion of the population than very small objects (excluding some motion impaired users) that fade into their surroundings (excluding some visually impaired users)

Simultaneously appealing to all users’ sense of play.

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2. Flexibility in Use: can be used equally well by both left and right-

handed users. can also be customized according to the skill

level of the user: novice users being presented with the minimal set of

physical objects necessary to complete their task expert users being given the facility to create

abstractions and have more freedom in their choice of physical-digital mappings.

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3. Simple and Intuitive Use: TUIs make use of the skills users have developed

over a lifetime of experience in the real world. This is complemented by the virtual component

of TUIs, which can both suggest possible actions and give interactive feedback regarding the effects of user actions.

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4. Perceptible Information: TUIs can communicate using:

tactile interaction (using static features such as object weight and texture)

haptic interaction (using time-varying features such as skin pressure and muscle tension).

Multiple modes of expression can be used for redundant presentation of essential information.

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5. Tolerance for Error: TUIs primarily make use of space as their

medium It gives a clear advantage in terms of error

tolerance because physical objects can easily be rearranged in space

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6. Low Physical Effort: physical objects of a TUI must not be light

enough to be moved accidentally. This requirement must be balanced against the

requirement that extended use of the TUI does not cause fatigue

the weights of the tangibles should be chosen to reflect this balance.

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7. Size and Space for Approach and Use: The physical objects themselves must be large

enough to be easily manipulated. However, the choice of object size should also

take into consideration the spatial area required by all of the physical objects

the full interaction space needs to be reachable by any standing or seated user.

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Inclusive Design of Tangible User Interfaces

Six defining principles of inclusive design (Nielsen, 1993):

1. Utility

2. Usability

3. Accessibility

4. Aesthetics

5. Trust

6. Stigmatisation and Desirability

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1.1. Utility:Utility: conceiving both new means for members of the

particular user group to perform existing tasks in a manner superior to existing methods

new tasks that provide functional or emotional value to the specific members of that group.

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2. Usability: To improve the user experience. phrased in terms of the five ‘E’s of usability:

Effective Efficient Engaging Error tolerant Easy to learn

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3. Accessibility: the fit between the available tools and the

capabilities of the user focused on the removal of access barriers.

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4. Aesthetics: Appealing, attracting and artistic. what one user group may find aesthetic might not

necessarily be so for other user groups E.g.: older adults versus teenagers

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5. Trust: The computer-like basis of TUIs may arouse suspicion

and distrust in elderly users who are not accustomed to such technology or who have had bad experiences in the past.

a clear benefit must be seen before trust can occur. The advantage of TUIs in this respect is their direct and

often task specific nature, which makes them more evidently beneficial than a general-purpose computer.

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6. Stigmatization and Desirability: Physical aids are often the source of

stigmatization for older adults – walking and hearing aids are good examples.

Novel interaction devices are more likely to arouse interest than stigmatization

Acting as a facilitator of conversation rather than condescension.

This in turn is likely to increase the desirability of such devices.

Documents

1 Chapter 4 Assistive Technology (AT) & User Interface