Accessible Web Design: What Are Sensory Characteristics?

As a web designer, you want your users to understand your content. They should be able to easily navigate, complete processes, and interact with your website. 

But if you’re providing instructions that rely on sensory perception, you’re leaving some users out of the conversation. 

The Web Content Accessibility Guidelines (WCAG) addresses this issue in Success Criterion (SC) 1.3.3, “Sensory Characteristics.” Here’s the full text of that criterion: 

Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, color, size, visual location, orientation, or sound.

In this context, a “sensory characteristic" is defined as an attribute that depends on a type of perception. That includes shape, color, spatial relationships, position, and any other information that is only available to people with a specific sense (potentially including taste, though fortunately, the internet isn’t quite there yet). 

Relying on sensory characteristics makes your content less useful

To create an accessible experience — and fulfill WCAG — you’ll need to exercise caution when using components with specific sensory characteristics. 

Why is that important? For starters, you don’t want to make assumptions about your audience. 

Some users may not be able to perceive content visually. Others might access your website with voice assistants or on slow internet connections; if they’re unable to process visual information, you still want them to be able to use your website. 

When you think about all of these users when designing your content, you build a more robust product. The experience is improved for every user — not just for people with disabilities.

Related: Five Strategies for Creating an Inclusive Design

Review instructions to make sure they don’t rely on sensory characteristics

WCAG SC 1.3.3 refers specifically to “instructions,” and accurate instructions are especially important for accessibility. They’re also important for delivering a functional experience for all users: If people can’t understand how your content works, they won’t use it. 

When designing your content and writing instructions for users, watch out for:

• Instructions that rely on color, shape, or position. For example, “click the red button" or “click the button on the right.” 
• Instructions that are not presented in text. You can certainly use audio and video content to keep your users engaged, but it’s important to have a text alternative for all visual or audio content. For example, if your product demonstration video advises users to “click below to get started,” that should also appear in the text below the video (ideally, with a full transcript of the multimedia). 
• Error notifications that rely on color alone. For additional guidance, read: Tips for Meeting WCAG's Requirement for "Error Suggestion."

Pay attention to your use of color

WCAG SC 1.3.3 overlaps with other WCAG standards, particularly SC 1.4.1, “Use of Color.” 

That criterion states that:

Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.

Here, it’s important to note that color can be used as one means of conveying information, but not as the only means. 

For example, many websites use the color blue to identify hyperlinks. That’s perfectly fine — but users need another way to identify links. If the links are also underlined, most users will be able to understand that they’ve found a hyperlink. 

Related: Use of Color for Accessibility Explained

To create accessible content, get into the habit of asking questions

When you’re using any type of sensory-specific characteristic, it’s helpful to ask questions: 

• If the images don’t load, is the page still functional, or does something break? 
• If color is removed, does everything still make sense?
• What has been added, besides color, to make important distinctions?
• Is this page usable for people who use screen readers? 
• What about people with hearing disabilities? 

These basic questions can guide you towards an accessibility-first mindset. As you learn more about accessibility, you should also consider creating user personas with disabilities, which can help your team craft an inclusive approach from day one. 

To learn more, download our free eBook: Developing the Accessibility Mindset. Or, if you’re ready to build a long-term, sustainable strategy for WCAG conformance, send us a message to connect with an expert.