Four principles of a well-coded page

Introduction

You've now read multiple ways you can make your content more accessible to all readers, but what is the overall intent of accessibility encoding? According to the official Web Content Accessibility Guidelines (WCAG 2.2) all web content must be perceivable, operable, understandable, and robust — an acronym known as POUR in the digital accessibility community.

There is certainly a Venn diagram with these principles. For instance, a well-designed study room reservation form that is easy to fill out on laptop or phone covers nearly the entire acronym. Think how hard it would be if the form didn’t tell you about your errors or how to correct them— that’s the two principles operable and understandable.

Closed captions in video make voices and sounds visual for people who cannot hear or clearly hear the soundtrack

Let's review these principles...

Perceivable

The perceivable principle states that content is presented so it could be understood with multiple senses — sight, hearing, and/or touch. For example, if a person cannot hear dialog in a video, closed captions allow them to read what is being spoken.

Operable

User interface components and navigation need to be operable with multiple input devices— be it mouse, touch, keyboard, voice, or specialized accessibility technology such as a tongue-controlled mouse. This ensures that all users, no matter a person’s motor abilities or dexterity, can readily interact with your content.

The interface also needs to communicate with the user about the status of interactive elements. For example, is a dropdown menu visible or closed? Without this description, a screen reader cannot navigate these interactive features. 

This principle also means on-screen buttons need to be large enough to easily touch on your phone, or that a menu system can work with a keyboard as readily as with a mouse.

Understandable

This principle states that content needs to be easy to read for the site’s audience. This includes using language that is appropriate for your website’s readership, avoiding jargon, and providing instructions for online interactions that are easy to follow. 

The Plain Writing Act of 2010 defines plain language as “Writing that is clear, concise, well-organized, and follows other best practices appropriate to the subject or field and intended audience.” Knowing your readers is key. The language being used in a corporate library website would be quite different from a school library website. 

Understandable also means your website behaves in a predictable manner. For instance, if you’re completing an online form, the form should clearly explain when you’re making mistakes and how to correct them.

Robust

To be robust, your content and site infrastructure must be compatible with a variety of browsers, device types, and assistive technologies now and into the future. This is especially important as we move quickly into the internet of things — for instance more than 20 percent of the world’s Internet users now have smart watches.

Learn More...