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CPACC - Module 7: web accessibility

A study summary of web accessibility for the CPACC exam — the WCAG standard, its POUR principles, the three conformance levels, and who else benefits.

  • #accessibility
  • #cpacc
  • #study-notes

This is Module 7 of Domain 2 of the CPACC (Certified Professional in Accessibility Core Competencies) Body of Knowledge — Web Accessibility. After the benefits of accessibility, this module gets concrete about the Web: what web accessibility is, and the WCAG standard that defines it.

Web accessibility is the ability of a website to be easily navigated, used, and understood by people with disabilities. It combines web development and file-creation standards with universal design practices. Per the W3C’s Web Accessibility Initiative (WAI): people must be able to perceive, understand, navigate, interact with, and contribute to the Web.

Other benefits of web accessibility #

People without disabilities #

Accessibility also helps people who don’t have a disability:

  • People on mobile phones and other small-screen/alternate-input devices.
  • Older people.
  • People with temporary disabilities (e.g., a broken arm).
  • People with situational limitations (e.g., bright sunlight).
  • People on a slow, limited, or expensive Internet connection.

Discoverability (SEO) and usability #

  • Website discoverability — WCAG overlaps with SEO. Accurate page titles help screen-reader users and describe content to search engines; captions are text, so search engines can crawl them.
  • Better usability for everyone — good color contrast, adequate line spacing, and plain language help all users, not just those with disabilities.

WCAG overview and structure #

The Web Content Accessibility Guidelines (WCAG, “WICK-ag”) are an internationally accepted set of technical standards for making web content more accessible, created by the W3C through its Web Accessibility Initiative (WAI).

Three levels of success criteria #

| Level | Meaning | |---|---| | A | Minimal accessibility | | AA (“double-A”) | Accessibility for most people — the most commonly used / targeted level | | AAA (“triple-A”) | Highest level of accessibility |

The four principles: POUR #

Web pages and applications must be Perceivable, Operable, Understandable, and Robust — remembered by the acronym POUR.

P — Perceivable #

Information and UI must be presentable in ways users can perceive — it can’t be invisible to all their senses (sight, hearing, and/or touch).

  • Provide text alternatives (alt text) for non-text content.
  • Provide captions and transcripts for multimedia.
  • Make content presentable in different ways (incl. by assistive tech) without losing meaning.
  • Make it easier to see and hear content.

O — Operable #

Users must be able to operate the interface — it can’t require interaction a user cannot perform.

  • Make all functionality keyboard-operable.
  • Give users enough time to read and use content.
  • No content that causes seizures or physical reactions (no flashing).
  • Help users navigate and find content (good focus order, descriptive links).
  • Make it easier to use inputs other than a keyboard.

U — Understandable #

Users must be able to understand both the information and the operation of the interface.

  • Make text readable and understandable.
  • Make content appear and operate predictably.
  • Help users avoid and correct mistakes.

R — Robust #

Content must be robust enough to be interpreted reliably by a wide variety of user agents, including assistive technologies — and stay accessible as tools evolve.

  • Maximize compatibility with current and future user tools.
  • Correctly expose the name, role, and value of elements.

Quick self-check #

  1. What three things does web accessibility combine?
  2. What does the POUR acronym stand for?
  3. What’s the current WCAG version, and which version is also an ISO standard (which number)?
  4. Name WCAG’s three structural layers.
  5. List the three conformance levels, and say which is most commonly targeted.
  6. Which principle covers keyboard operation? Which covers alt text? Which covers future-proof compatibility?

Knowledge check #

Answer each question, then check — the feedback explains every choice.

Knowledge check

1. The POUR principles are the highest level of standards in the guidelines.
2. Web accessibility combines… Select all that apply.
3. To meet WCAG 2.2 Level AA, a page must also meet all Level A success criteria.
4. Captions can be crawled because they're text, so captions also help improve…?
5. Why is enough color contrast a good design practice?
6. Which principle ensures a web page works with a keyboard?
7. Which principle ensures images include alternative text?
8. Which principle ensures a technology is compatible with current and future technologies?
9. Which principle ensures a page has no flashing content?
10. To support people with low hearing, pre-recorded videos should always include…?

Study tip: this is the most testable module in Domain 2. Lock in POUR (and that it’s principles, not levels), the A/AA/AAA levels (cumulative; AA is the target), WCAG 2.2 / ISO 40500, and the Principles → Guidelines → Success Criteria structure. Then practice matching a requirement (keyboard, alt text, no flashing, compatibility) to its POUR principle — that’s the exam’s favorite drill.