Accessibility Fundamentals Week 1

posted by Maddy

I am studying for the Web Accessibility Specialist certification by the International Association of Accessibility Professionals (IAAP). Every week I will be studying independently and then reveiwing the content for the week with some of my colleagues. This week we are reviewing 'Introductory Materials' to web accessibilty which consists of disabilities, guidelines, and Laws.

Disabilities

Blind - Uses a screen reader to listen to web pages

Design Considerations

  1. All Content must be presented in text or via a text equivalent
  2. All functionality must be available using only the keyboard
  3. Content must use markup w. good structure and semantics
  4. All custom controls (e.g. expand/collaspe divs, dialogs, volume controls) must have the correct name/label, role and value
  5. Users must receive immediate feedback after all actions
  6. videos require audio descriptions
  7. Mobile: all features require a click action. Custom swipe actions on web pages will not work with screen reader turned on

Low Vision - Uses Screen Magnification, screen readers and, color customization

Design Considerations

  1. Pinch-to-zoom feature must not be disabled.
  2. All text must pass contrast guidelines against the background
  3. Links, buttons, and controls must have a visible :focus and :hover state.
  4. UI should provide a clear visual distinction between content (text) and controls(buttons,links,etc)

Color Blind - There aren't many assistive technologies. Enchroma are glasses that help compensate.

Design Considerations

  1. All information must be understandable without needing to distinguish between colors

Deaf - Most of the Web is accessible -- the concern is accessibility of audio

Design Considerations

  1. All videos must have captions
  2. All audio-only content must have transcripts

DeafBlind - Uses a braille output device and screen reader

Design Considerations

  1. All considerations of blindness apply
  2. All considerations of deafness apply
  3. Transcript must be provided for audio and video content (subtitles will not suffice)

Motor Disabilities - Keyboard w. mouth stick, one handed keyboard, expanded keyboard, speech recongnition

examples: a temporary inability to use a single hand due to an injury, to diiffculty u both hands, all the way to having little to no motor control of your limbs.
Design Considerations

  1. All functionality must be available using only the keyboard.
  2. Links, buttons, and controls must have a visible :focus and should have visible :hover
  3. Warn users before time runs out on session time-outs and give an option to extend (recommended min response time is 2 min).

Speech Disabilities - Use AAC (Augmentative and Alternative Communication)

Design Considerations

  1. Don't depend on voice input

Cognitive Disabilities (MOST COMMON TYPE OF DISABILITY) - no tech mediation

Design Considerations

  1. For users with lower comprehension
    • Simplify interface
    • Simplify content
    • Keep videos and audio short
    • limit number of choices
    • Provide help features
    • Design for ease of use
    • Test the usuability with actual users
  2. For users with memory loss
    • Retain information across screens, and within a path
    • Provide help features
  3. For users with distractibility
    • Reduce or eliminate distractions

Reading Disabilities(Cognitive Disability) - some use different browser fonts

Design Considerations

  1. Supplement text with illustrations, videos, audio
  2. avoid the highest level of contrast for text against background ( but stay within constrast range for low vision)

Seizures - no tech mediation

Design Considerations

  1. Don't include videos, animations, or transitions with flashing light sequences of 3 times or more per second.

Multiple Disabilities

Design Considerations

  1. Consider all of the above disabilities in various combinations.

Guidelines

(WCAG 2.1 Guidelines)[https://www.w3.org/TR/WCAG21/] published in 2018 by (W3C)[http://www.w3.org/] are regarded as most authoritative source of accessibility guidelines in the world. Previous version 2.0 was published in 2018 and accepted as ISO (International Standards Org) in 2012.

Levels : A, AA, AAA

Levels correspond to conformance to guidelines ( A == Lowest, AAA== Highest). Many companies strive for AA but, AAA is required for at least some people with disabilites.

The 4 Main Principles ( & The 13 Guidelines)

  1. Perceivable - Info and UI components must be presented to users in ways they can perceive.
    1.1 Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, speech, symbols or simpler language.
    1.2 Provide alternatives for time-based media.
    1.3 Create content that can be presented in different ways (for example simpler layout) without losing information or structure.
    1.4 Make it easier for users to see and hear content including separating foreground from background.
  2. Operable - UI components and navigation must be operable ( by keyboard or mouse )
    2.1 Make all functionality available from a keyboard.
    2.2 Provide users enough time to read and use content.
    2.3 Do not design content in a way that is known to cause seizures.
    2.4 Provide ways to help users navigate, ifnd content, and determine where they are.
    2.5 Make it easier for users to operate functionality through various inputs beyond keyboard.
  3. Understandable - Info and operation of UI must be understandable
    3.1 Make text content readable and understandable.
    3.2 Make Web pages appear and operate in predictable ways.
    3.3 Help users avoid and correct mistakes.
  4. Robust - Content must be robust enought that it can be interpreted reliably by a wide variety of user agents, including assistive technologies
    4.1 Maximize compatibility with current and future user agents, including assistive technologies.

Success Criteria and Conformance Levels

The success criteria are the rules, or checklist items, upon which the guidelines are based. The name suggests that if you meet the criteria, y successfully met the guideline, and that portion of the web content will be accessible to people with disabilities.
For more see: https://www.w3.org/WAI/WCAG21/Understanding/conformance#levels

"Sufficient Techniques" and "Advisory Techniques"

Some of the Criteria are self-explanatory but for those more ambiguous Criteria, there is an additional level in the documentation that lists techniques for achieving the succes criteria. Meeting all of the "sufficient techniques" == passing the success criterion.
Adivsory Techniques are good ideas or best practices (aren't considered critical).
Techniques exist for HTML, CSS, SMIL, client-side scripting, server-side scripting, Flash, PDF, Silverlight, and ARIA.

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