Provide Text Descriptions for Images and Graphics
For help, contact: Karen Sorensen
Why this is Important
The purpose of this guideline is to ensure that all non-text content (e.g., graphics, photos) is also available in text. "Text" refers to electronic text, not an image of text. Electronic text has the unique advantage that it is presentation neutral. That is, it can be rendered visually, auditorily, tactilely, or by any combination of the three. Electronic text can be presented in whatever form best meets the needs of the user. It can also be easily enlarged or spoken aloud so that it is easier for people with reading disabilities to understand.
Citation: "Using alt attributes on img elements," W3C World Wide Web Consortium Note. (URI: http://www.w3.org/TR/UNDERSTANDING-WCAG20/text-equiv.html)
How to Achieve this Accessibility Guideline
Simple Images and Graphics
If you insert (don't copy and paste) an image in a document or web page, assign it an alternative text description (ALT text). Most applications including Desire2Learn and Microsoft Word prompt you to provide ALT text before uploading an image. The ALT text should describe the purpose of the non-text content so that the user of the screen reader knows what the graphic is and why it is important.
Example: A photograph of two world leaders shaking hands accompanies a news story about an international summit meeting. The ALT text says, "Brazilian President Luiz Inacio Lula da Silva (L) and Chinese President Hu Jintao (R) shake hands. President Obama watches." If you know how to turn off images in your browser, you will see the ALT text.
For images and graphics that are purely decorative, give it an ALT text in the form of an empty quote ("").
Complicated Images and Graphics
ALT text should really be limited to 100 characters, which isn't enough if you have a complicated image or graphic. If that's the case, include a thorough description of the image or graphic in the content of your document. If it's a presentation, include the thorough description in the notes panel of the presentation and make notes available to all viewers of the presentation.
Tabular data in an MS Office documents also needs ALT text to give a summary of what the table is about.
For Microsoft Word 2010: Right click on the table, and select "Table Properties". There will be an ALT Text tab. Click on that and fill in the ALT text just as you would for an image.
For PowerPoint 2010: Right click on the table, and select "Format Shape". Choose the ALT Text menu item and fill in the ALT text just as you would for an image.
- Writing Good ALT Text
- WebAIM: How to add Alternative text for images in MS Word documents
- Guidelines for Describing STEM (Science Technology Engineering and Math) images
- How Do We Access Meaning in Art? (Describing art images in alt text)
- Effective Practices for Description of Science Content within Digital