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Phase 3
Accessibility Guidelines (WCAG basics)
Accessibility is not an edge case; it is a core component of great design that ensures products are usable by people of all abilities. This module introduces the Web Content Accessibility Guidelines (WCAG), the global standard for digital accessibility. We will break down the four foundational principles—Perceivable, Operable, Understandable, and Robust (POUR)—and explain the different conformance levels (A, AA, AAA). By the end, you’ll understand why accessibility is a legal, ethical, and business imperative, and you’ll have a foundational framework for designing more inclusive products.
The Four Principles of WCAG (POUR)
WCAG is organized around four high-level principles that form the foundation for web accessibility. For a product to be accessible, its content and functionality must be:
Perceivable
Users must be able to perceive the information being presented. It can't be invisible to all of their senses.
- Provide text alternatives for images.
- Offer captions for videos.
- Ensure high contrast between text and background.
Operable
Users must be able to operate the interface. The interface cannot require interaction that a user cannot perform.
- Make all functionality available from a keyboard.
- Give users enough time to read and use content.
- Avoid content that could cause seizures (e.g., flashing lights).
Understandable
Users must be able to understand the information as well as the operation of the user interface.
- Make text content readable and understandable.
- Make web pages appear and operate in predictable ways.
- Help users avoid and correct mistakes.
Robust
Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.
- Maximize compatibility with current and future user agents.
- Ensure assistive technologies can understand the content.
Why Accessibility Matters
Designing for accessibility is not just a compliance checkbox; it is a strategic advantage that improves the experience for everyone.
- Expands Market Reach: Inclusive products are available to a wider audience, including the millions of people with disabilities.
- Enhances Brand Reputation: Demonstrates a commitment to social responsibility and inclusivity.
- Improves Overall UX: Features designed for accessibility, like captions and high contrast, often benefit all users (the "curb-cut effect").
- Reduces Legal Risk: Adhering to standards like WCAG helps mitigate the risk of accessibility-related lawsuits.