Week 9 Accessibility Flashcards
Accessibility
“Accessibility refers to the extent
to which the use of an application
or service is affected by the user’s
particular functional limitations
or abilities.”
Range of Disabilities (VAPS-CoLLeN)
Visual
Audio
Physical
Speech
Cognitive
Language
Learning
Neurological
Accessibility is whose responsibility?
“Accessibility is everyone’s responsibility.”
Why Does Accessibility Matter?
Morally/ethically right
Tech has potential to increase “haves” and “have-nots” in society
Acceptability depends on usability and accessibility
HCI Accessibility
For any individual user, for each user task, there is a
sequence of accessible input actions and associated
feedback for successful accomplishment.
User Diversity Factors (6)
Disabilities and impairments
* Physical disabilities
* Situationally-induced impairments
* Sensory impairments
* Learning disabilities, developmental disorders
Skill level, e.g.,
* Novice
* Expert
Cognitive factors, e.g.,
* Memory
Socio-economic factors
* Digital literacy
* Digital access
* Digital devices
Cultural and linguistic issues
* English vs. non-English speakers
Demographic factors
* Age: children vs. older users
Accessibility and Regulations in Canada
Accessibility for Ontarians
with Disabilities Act
(AODA - 2005)
Accessible Canada Act
(ACA - 2019)
Government websites
must be accessible, and
follow the standard on Web
Accessibility
Assistive Technologies, what are both branches?
Hardware & Software
Assistive Technologies
Promote greater independence for people with disabilities
Provide enhancements or modified methods of interacting with the technology
Enable tasks formally unable or difficult to accomplish
* Chrome screen-reader
* Visual & vibro-tactile direction indicators
Alternative Devices Examples
- Alternative keyboards
- Larger keys, one-handed, Braille
- Alternative pointing devices
- Gesture, eye movement
- Mouth or head-mounted devices
- Joysticks, trackballs, touchscreens
- Braille printers/displays/notetaker
- Interaction through breath
Hardware Assistive Technology: Shortcomings
Reproducing instead of redesigning
Requires extensive configuration/customization
Implementation/translation barriers
* How do we reproduce graphical images in non-visual form?
* How do we drag & drop for blind users?
Compatibility
Reactive in nature
* rather than proactive
Assistive Technology: Software Solutions Examples
- Voice synthesizer
- Voice recognizer
- Screen readers
(JAWS) - Text predicter
- Screen magnifiers
- ChatGPT
Accessibility integrated into OS
Font sizes, colors
Customization of pointer, sounds
FilterKeys
* Prolonged pressing ignored
* Speed of key repetition customizable
MouseKeys
* KB as a pointing device
Universal Access/Design
Accessibility and usability of IT by…
* anyone, anywhere, anytime, and through any media and device
Shifts focus from assistive tech to universal access
Avoid need for post adaptations
Also focus on any person who may differ
with respect to…
* language, culture, computer literacy, or
* other characteristics that put them at
risk for exclusion
- Equitable Use
Provide same means of use for all users:
Provisions for safety, privacy, security
equally available for all users
Appealing to all users
- Flexibility in Use
Offer choice in methods of use
Accommodate left and right-handed use
Facilitate accuracy/precision
Adapt to user’s pace
- Simple and Intuitive
Eliminate unnecessary complexity
Consistent with user expectations
Accommodate wide range of skill
Arrange info in order of importance
Provide effective prompts/feedback
- Perceptible Information
Use redundant modes of presentation
Provide adequate contrast between
info/surroundings
Maximize legibility
Differentiate elements in ways that
can be described
- Tolerance for Error
Arrange elements to minimize hazards
Provide fail safe features
Discourage unconscious action in
tasks that require vigilance
Accessibility for Everyone, Everywhere, Anytime. UI works well…
UI works well…
in noisy environments
in situations where it is unsafe to look
at the device
for people with occupied hands
for people distracted, tired, stressed,
in traumatic situation
Whom Does Web Accessibility Benefit?
Everyone, people with or without disabilities
Whom Does Web Accessibility Benefit? People Without Disabilities
People using devices with smaller and
bigger screens
Older people with changing
abilities due to ageing
People with “temporary
disabilities”
People with “situational
limitations”
People using a slow Internet
connection
Common Barriers
Images without alternate text
Misleading use of structural elements
Uncaptioned audio or undescribed video
Lack of alternate information for scripts
Tables that are difficult to decipher when
linearized
Poor colour contrast
Standards Bodies Promoting Web Accessibility? Which companies
W3C and WAI
Web Content Accessibility Guidelines (WCAG)
WCAG 1.0 * May 1999
WCAG 2.0 * Dec. 2008
WCAG 2.1 * June 2018
WCAG 2.2 * Oct. 5, 2023
W3C Guidelines
- WCAG 2.2 has 13 guidelines under 4
principles (POUR)
- Perceivable
- Provide text alternatives for non-text content.
- Provide captions and other alternatives for
multimedia. - Create content that can be presented in different
ways, including by assistive technologies, without
losing meaning. - Make it easier for users to see and hear content
- Operable
- Make all functionality available from a keyboard.
- Give users enough time to read and use content.
- Do not use content that causes seizures or physical
reactions. - Help users navigate and find content.
- Make it easier to use inputs other than keyboard.
- Understandable
- Make text readable and understandable.
- Make content appear and operate in predictable
ways. - Help users avoid and correct mistakes.
- Robust
- Maximize compatibility with current and future
user tools.
Components of Web Accessibility
Web content
Web browser
Authoring tool
Evaluation tools
Assistive technology
Users’ knowledge and experiences
Developers
The Implementation Cycle (1) (Try and understand blankish slides on this)
slide
Interdependencies Between Components (Slide 51) but maybe just list the steps
Technical specifications, WAI Guidelines Authoring , Tools Developers Evaluation Tools, User Agents/Assistive Technologies, Users
Adding Alternative Text: Three (3) Basic Types of Images
- Decorative: Don’t add information to the content of a page
- Informative: Convey a simple concept or information that
can be expressed in a short phrase or sentence - Functional: Used to initiate actions rather than to convey
information
