1.3.3 Sensory Characteristics: Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound.
As part of the WCAG 2.0 Perceivable principle, SC 1.3.3 Sensory Characteristics requires that all users have access to instructions for understanding and using content (i.e., be able to perceive and understand them) without relying solely on sensory characteristics such as shape, size, relative spatial location, orientation, or audible cues. The SC does not prohibit the use of sensory characteristics to provide user instructions. However, when content creators use sensory characteristics to provide instructions, they must also provide alternative means for understanding the instructions.
For example, a Web page might direct users to “select the arrow to the right of the image to navigate to the next image.” An AT user might not be able to determine the location of the arrow in relation to the image, which could make it confusing for the user to navigate the content.
If, on the other hand, the Web page provides a “Next” label for the arrow and provides instructions for the user to “select the arrow below the image labeled ‘Next,’ to navigate to the next image", the addition of the text identifier provides enough information for users to perceive and understand the instructions without relying solely on sensory characteristics.
Impact of Nonconformance with SC 1.3.3 Sensory Characteristics
| Type of Disability | Description of Impact |
|---|---|
| 302.1 Without Vision | Users who are blind cannot use a mouse to interact with electronic content and typically use an assistive technology, such as a screen reader, to get audible or other alternative output for the information represented visually. To be able to navigate the content, understand its structure and relationships, and understand the meaning of content represented in graphics and images, the content must provide textual and programmatic cues in addition to the content presented purely visually. |
| 302.2 With Limited Vision | Users with limited vision may have widely different visual perception. Individuals with limited vision may or may not use assistive technologies. Therefore, in addition to textual and programmatic cues necessary for assistive technologies, ICT must also present content consistently and predictably. Users who view content with magnifiers may not pick up alerts, warnings, or other content if such content is presented outside of a consistent and predictable navigation pattern or if the content is not itself viewable at large magnification. Content that becomes distorted when magnified can also prevent some users with limited vision from being able to understand or interact with the content. |
| 302.3 Without Perception of Color | Some users may not be able to perceive differences between certain colors, and therefore do not receive information conveyed by the colors (e.g., using gradients of color between red, yellow, and green to indicate an item’s status from poor to good). In such cases, ICT must provide additional information by alternative means that conveys the same meaning (e.g., shapes and/or textual labels in addition to the color). |
| 302.4 Without Hearing | When ICT provides information, instructions, or cues audibly, users who are deaf will not receive the information. Typically, providing the same information visibly (e.g., providing a warning light or textual dialog to accompany an audible warning sound or captions for audio dialog and other audible information in a video) will enable users who are deaf to get equivalent information. |
| 302.5 With Limited Hearing | Some users cannot hear sounds below certain volumes or at certain frequencies and may not be able hear certain audio outputs from ICT. Background noise can also be problematic for users with limited hearing. Providing modes of operation that enhance audio clarity (e.g., filtering out hisses and pops, blocking sounds at specific frequencies, normalizing voice volumes, removing constant tone patterns), increase the range of volume, increase volume at higher frequencies, and/or give users control over such settings can help users with limited hearing understand, navigate, and operate the ICT. Users with limited hearing may also benefit from some of the same methods used to provide information to users without hearing. |
Applicability of Success Criteria 1.3.3 Sensory Characteristics
| Technology | Applicability of SC 1.3.3 |
|---|---|
| All (Web, Software, Office documents, PDFs, Mobile Native) | Applies directly; developers must provide additional information to clarify anything that depends solely on sensory characteristics to convey information, regardless of format or technology in which the information is presented. |