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POUR - Accessibility Principles

The POUR principles, established by the W3C, consist of four fundamental guidelines that form the basis for making a mobile app accessible to all users.

Perceivable

Information and user interface components must be presentable to users in ways they can perceive.

What to do?

Users typically perceive and interact with information presented in an app through sight, sound, and, in some instances, touch.

The goal is to offer alternative ways for users to access information to accommodate senses that may be weaker or absent.

Examples

Operable

User interface components and navigation must be operable.

What to do?

We must ensure the app is compatible with assistive technologies, including keyboards, switches, and screen readers. Also, we must provide enough time to complete and correct tasks.

Examples

Understandable

Information and the operation of user interface must be understandable.

The Understandable principle includes guidelines for readable content, predictable content, and input assistance.

What to do?

We must use clear language and functionality that are easy to understand. Additionally, maintaining consistent patterns helps users anticipate outcomes.

Example

  • The app should use a navigation structure that is both predictable and consistent
  • Abbreviations, jargon, and reading levels should be avoided to ensure the app is accessible to a broad audience
  • Elements should be consistent in style and behave consistently and predictably to avoid confusing users
  • No two identical-looking controls should function differently. The inverse is also true; two controls with the same function should have the same appearance
  • The app should provide clear feedback for user actions and effective error handling to guide users in correcting mistakes
  • Contextual help and error prevention mechanisms should be in place to assist users in navigating the app more effectively

Robust

Content must be robust enough that it can be interpreted by a wide variety of user agents, including assistive technologies.

We must ensure that our app functions effectively across various devices, including assistive technologies.

Example

  • Components should be clearly defined with appropriate names, roles, and values
  • Messages like "added to cart" should be conveyed to the user in a way that doesn't interrupt their workflow or shift their focus

External references