POUR

The acronym representing the four high-level principles that guide the Web Content Accessibility Guidelines (WCAG). These principles were developed by the World Wide Web Consortium (W3C) to shift the focus from a simple checklist of fixes to a functional understanding of how users experience digital content.

Under the POUR framework, if a website or application fails to meet any one of these four criteria, users with disabilities will find the content difficult or impossible to use.

Perceivable

Information and user interface components must be presentable to users in ways they can perceive. This means users must be able to comprehend the information being depicted; it cannot be invisible to all of their senses.

• Text Alternatives: Providing alt text for images so they can be converted into speech or braille.
• Time-based Media: Providing captions, transcripts, or audio descriptions for video and audio content.
• Adaptable Content: Creating content that can be presented in different ways (e.g., a simpler layout) without losing information or structure.
• Distinguishable: Making it easy for users to see and hear content, including separating foreground from background (e.g., high color contrast).

Operable

User interface components and navigation must be operable. The interface cannot require interaction that a user cannot perform.

• Keyboard Accessible: Making all functionality available from a keyboard alone, without requiring a mouse.
• Enough Time: Providing users enough time to read and use content (e.g., preventing session timeouts or allowing users to pause moving content).
• Seizures and Physical Reactions: Not designing content in a way that is known to cause seizures (e.g., avoiding rapid flashing).
• Navigable: Providing ways to help users navigate, find content, and determine where they are (e.g., clear page titles and skip to content links).

Understandable

Information and the user interface’s operation must be understandable. Users must be able to understand the information and the operation of the interface.

• Readable: Making text content readable and understandable (e.g., identifying the primary language of the page and defining unusual words).
• Predictable: Making Web pages appear and operate in predictable ways (e.g., navigation menus stay in the same place across the entire site).
• Input Assistance: Helping users avoid and correct mistakes (e.g., providing clear error messages and instructions for forms).

Robust

Content must be robust enough to be interpreted reliably by a wide variety of user agents, including assistive technologies. As technologies and user agents evolve, the content should remain accessible.

• Compatibility: Maximizing compatibility with current and future user agents, including assistive technologies (e.g., using valid HTML so that screen readers don’t break when parsing the code).
• AI Enhancement: Utilizing AI-driven automated testing to ensure that, as code updates are pushed, the robustness of the accessibility layer is maintained through continuous integration (CI) pipelines.