Issue Category: Major
The HTML content contains images that don’t have a description or alternative text. People with screen readers or other assistive devices rely on these descriptions to understand the image content and purpose. Having a clear description for an image can help everyone better understand the content of the image and how it relates to the context.
If your image lacks a text description, the Ally indicator will appear “red.” Selecting the indicator will reveal that the file is only 25% accessible because it lacks an alternative description. Click the “What this means” button for an explanation, and “How to write a good description” for some quick tips.
When you’re ready, simply add your alternative description to the text field in the Ally feedback window. You can also edit existing text in the box. When you’re done, select “Add.” Make sure your description is more than just the title of the file, or Ally will report an accessibility error. Describe the image and what’s important, and mention any text in the image to improve your score.
If your image is only for visual affect, and does not contain info relevant to the learning content, you can also mark the image as “decorative.” This means no alternative description is necessary, and your accessibility score will improve. This helps assure students of the purpose of those files.
Adapted from Blackboard Ally: Add Alternative Description for Image Files