The Four Pillars of Web Content Accessibility Guidelines (WCAG)
Understanding the basic philosophy of WCAG accessibility standards.
The United Nations has stated that access to information is a basic human right. This is the basic tenet of accessibility – that all information, especially information found on websites and software, should be easily available to any person, regardless of ability. There are laws, standards, and guidelines that outline how making information accessible can be accomplished. The most widely accepted standards are the Web Content Accessibility Guidelines (WCAG). WCAG is an international set of rules developed by the World Wide Web Consortium (W3C) in order to provide a technical standard for web content accessibility. These technical standards are based on four pillars of accessibility that define how information should be presented digitally. WCAG 2 are the standards adopted by the governments of Australia, Canada, France, Germany, Hong Kong, India, Italy, Ireland, Israel, Japan, Netherlands, New Zealand, Norway, Spain, UK, and the US to measure digital accessibility in your organization. WCAG 2.1 was released in June 2018 and builds upon the previous version without alteration to previous standards.
According to WCAG, information that is presented digitally should be:
Let’s discuss these pillars one by one.
- Perceivable. This means that all information and functionality cannot be invisible or inaccessible to all of an individual’s senses. Thus far we have no way to smell or taste the internet, but until then users must be able to see or hear or feel the information being provided. This means that if content cannot be seen, it must be able to be heard or felt (for example, by using a connected Braille display); if it cannot be heard, it must be able to be seen or felt. All content must be able to be perceived and read by users, regardless of how they access the information (mouse, keyboard, screen reader, etc.). There should be a non-text alternative for all text and text functions. Some examples of “perceivable” include alt text for images and captions on videos, color contrast practices such as red text not being used against a green background (no matter how festive it feels) as 8% of men have red/green color blindness. Content should be easy to see or hear or feel with a connected Braille display, and it should be easy to locate.
- Operable. This means the website should be functionally usable no matter how it is accessed. Buttons should work regardless of whether someone is using a keyboard, a mouse, a touchscreen, a joystick, or any other input mechanism. Users should be able to navigate through the content easily. The content should not produce seizures (for example from flashing lights or content) and should allow enough time for users to react to information presented, even if their level of mobility makes them slow to respond. There should be no “keyboard traps” (places where you can tab onto an element but are unable to tab back out).
- Understandable. This means the content should be able to be understood by all users. It should not be so complex or difficult to read that users cannot use the information. It should not be overly technical. This is also common sense. If the information is too difficult to understand, users will be unable to make use of the website as intended and the purpose of the content will not be fulfilled. Example: forms should be clear and easy to fill in – terminology should be as clear as possible. Names of objects (such as buttons, links or other interactive elements) should be consistent when used in multiple locations (rather than using “buy” in one place and “add to cart” in another, one label should be used for all identical functions). The language presented visually should be the same as the language coded into the website so that the screen reader is reading it in the correct language. I once saw a mistake in coding result in an unexpected change of language for screen reader users from English to French right in the middle of an exam.
- Robust. The content should be usable with a variety of technologies, assistive and otherwise, and remain usable as technology changes. Example: a video should work regardless of the browser or device on which you are trying to watch it. Another example is that many websites simply do not function properly on a smartphone. Content is misplaced visually, fields cannot be accessed, or settings can only be reached via a right click from a mouse (something that someone accessing the content on a smartphone or using a screen reader may not have or be able to use).
The goal of these standards is for your organization’s digital information to reach everyone, regardless of how they access that information. This means you need to remain familiar with both accessibility standards and changing technology. With one in four adults found in the CDC’s latest report to have a disability, you can be sure that a large part of your target audience has a need for accessible content in order to do business with your organization. Accessibility should be an integral part of your organization and mold how your digital content is created and provided to your audience.
The philosophy of these four pillars is the foundation of all success criteria in the web content accessibility guidelines.
They also cover more than the specific guidelines can: questions such as “what is simple language?” Simple to whom? In what context? If your online content meets these basic pillars of the WCAG philosophy, it will meet or exceed the individual standards found in WCAG.