Canvas - Rich Text Accessibility Checker Released
Posted: 2017-10-30 10:29:59 Expiration: 2017-11-24 13:29:59
The Rich Content Editor Accessibility Checker assists instructors and course designers to maintain accessibility requirements in Canvas content. This tool only verifies content created within the Rich Content Editor.
All components are designed according to the template set in the institution’s Theme Editor.
This tool verifies the following accessibility rules:
- Table captions: Tables should include a caption describing the contents of the table.
- Table header scope: Tables headers should specify the scope and the appropriate structure.
- Table header: Tables should include at least one header.
- Sequential headings: Heading levels should not be skipped (e.g. H2 to H4). However, the tool does not check if the first header starts with H2 or whether the headings are sequential with the rest of the content in the page. Tables do not begin with H1, which is allotted to the page title.
- Heading paragraphs: Headings should not contain more than 120 characters.
- Image alt text: Images should include an alt attribute describing the image content. In an upcoming release, alt text can be included when uploading an image to help minimize this error. Additionally, users can identify the image as decorative, which do not require alt text.
- Image alt filename: Image filenames should not be used as the alt attribute describing the image content. Currently, files uploaded directly to Canvas create a redirect that does not properly verify image filenames, which will be corrected in an upcoming release.
- Image alt length: Alt attribute text should not contain more than 120 characters. In an upcoming release, alt text can be included when uploading an image to help minimize this error.
- Adjacent links: Adjacent links with the same URL should be a single link. This rule verifies link errors where the link text may include spaces and break the link into multiple links.
- Large text contrast: Text larger than 18pt (or bold 14pt) should display a minimum contrast ratio of 3:1.
- Small text contrast: Text smaller than 18pt (or bold 14pt) should display a minimum contrast ratio of 4.5:1.
Note: For text contrast, the Accessibility Checker verifies color using the same calculations as the WebAIM tool. However, currently, the checker only verifies against Theme Editor templates with High Contrast Styles. To verify color contrast, enable High Contrast Styles in user settings before enabling this feature.
-- Learn@UW Mad: Dale Johnson