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The POUR Accessibility Principles

What is accessibility?

It's the practice of ensuring that all users have equal access to information and functionality, regardless of disability. 

According to the World Wide Web Consortium, to be accessible, web content must be:

  • Perceivable,
  • Operable,
  • Understandable and
  • Robust,

Which spells out the acronym, POUR.


Most people perceive web pages or digital documents by looking at them. They rely on their ability to see. However, some people experience low vision, or may be blind. In this case they need to perceive the web in some other way. Sound is often a good alternative, and screen reader software can be used to convert digital text into synthesized speech.  

For those who cannot see or hear, there is one more sensory modality that may be available for perceiving the web: touch. Digital text can be converted into Braille, three-dimensional characters with raised dots that represent the alphabet and other characters and symbols. There are modern refreshable devices that scan a web page and convert the digital text into Braille. These devices present one line of text at a time, allow the user to feel it, then move on to the next line of text.

Understanding the alternative methods your audience could use in order to perceive your web page is important. Digital text is universally accessible because it can be converted into other formats, such as audio or Braille.

To make your web pages or digital documents as accessible as possible, then, you should provide digital text for every element on your page. In addition to writing the main content on your page, include captions for your photos, provide alternative text (or image descriptions) to be read by screen readers, and include transcripts for audio or video content. You can make dynamic elements on your page, such as an expandable list, accessible as well by using ARIA (Accessible Rich Internet Applications).


Operability is about how your audience inputs information on the web. This can include using input devices like a mouse, keyboard, touchscreen, voice recognition software, or other specialized input devices. All features, and especially those related to navigation or dynamic elements, need to be functional no matter what kind of input device a person uses.

For an example, consider a student who has had major surgery on a hand or arm and is not able to use the mouse. This student may rely on the keyboard in order to navigate, so your web page needs to allow for keyboard navigation into every drop-down menu, the ability to select a link in that menu, or move past the menu and into another element of your page.

Also consider students who use their phones to access your web pages or digital documents. They need to be able to access the same features a desktop user has when certain events are triggered when the mouse hovers over an item-as of yet, our touchscreen devices do not sense when your finger hovers over an item on the screen, all you can do is click.

Typically you won't need to worry about operability if you are relying on the CMS Editor.


Not only does your web section and digital content need to be perceptible by the user, but he or she also needs to be able to comprehend. Some general design tips to help with comprehension include avoiding unnecessarily complicated information, limiting unfamiliar terminology, and providing supplemental formats such as images, audio, and video. If you are using multiple languages on your page you will need to specify the language that way a screen reader will correctly pronounce the words. 

The visual layout of your web page or digital content also affects comprehension. This is why every web page under the domain contains the top and side navigations bar and bottom resource footer. This visual layout remains consistent so that people interpret BSD44's web pages as coherent, interrelated content within the context of the district.


Robust content is that which is compatible across multiple platforms, from Google Chrome to Edge, Windows to Mac, or Android to Apple's iOS. It is impossible to support every possible platform, as each browser or device experiences version updates and there are many alternative platforms in addition to those most commonly used. But, there are certain steps you can take to maximize the robust nature of your web sections or digital content.

One of the best ways to maximize robustness is to use standard markup. This will be taken care of if you use the CMS Editor.