Alternative (alt) text is a textual substitute for non-text content within your course materials. Alt text is descriptive text that conveys a visual item's meaning and context in a digital setting. Knowing when and how to include alt text for images, graphs, and other visuals is important. Alt text helps individuals to understand images and other visual (graphical) content. Screen readers describe visuals by reciting the alt text provided.
When asked to provide alt text, you should consider how you would respond to these questions:
- Why is the image, chart or graph included?
- Who is the intended audience?
- If there is no description, what would a student using a screen reader or text-to-speech software miss from your course material?
Your responses should be used to craft the text that will describe aspects of your course content, so screen readers know how to describe those elements to students. First, you will need to determine the type of alternative text descriptions you should include. There are several types of images that you may add to course content and how you respond for each type is different.
Types of Images, Charts, and Graphs
- Informative images represent a concept.
- They include pertinent information that the learner requires to succeed with the course content.
- Decorative images are added for visual appeal to your material.
- The user does not require the meaning of these images.
- Decorative images can and should be marked as such. This tells assistive technology to pass over this image as it does not convey information the learner needs to succeed with the course material.
- Functional images are those that encourage action.
- The user viewing these may have been conditioned to know that clicking these images will do something. For example, email and printer icons.
- Keep descriptions simple by focusing only on the function/action being performed.
- Complex images are those that contain a lot of information.
- Complex images can be those videos or diagrams that describe complex systems, flowcharts that depict extensive workflows, or graphs that show a lot of data.
- Complex images, graphs, and videos should be described in sufficient detail for success with the course content.
- Alt text must also be included for embedded videos to describe the visual experience, including the content and purpose of the video.
- Consider integrating descriptions into your content on the slide.
The key takeaways for alt text are determining the purpose of the image. Mark decorative images so they are not read by screen readers and describe informative images and icons. Keep alt text short unless the figures require a more detailed explanation to be fully understood by the learner.
You can begin to write and add alt text after deciding on the type of visual you are using. The process is simple but can vary slightly by application.
Alternative Text for Visuals in Microsoft Word and PowerPoint
- Open a Word Document or PowerPoint Presentation.
- Insert an image.
- Click the image.
- Open the Alt Text window on the Picture Format tab of the ribbon.
- Type a brief, meaningful alt text description in the dialog box.
- Check the Mark as decorative box if the image is not important and should not be read by the screen reader.
- Repeat process for all images, charts, and other visuals.
Alternative Text for Visuals in the Canvas Rich Content Editor (RCE)
- Open the Rich Content Editor (RCE).
- Insert an image.
- Click the image and open the Image Options menu.
- Add Alt Text for the image.
- By default, the Alt Text field displays the image file name. Screen readers read alt text, and it displays when an embedded image cannot display.
- Check the box for Decorative if the image does not require alt text to be read.
- Click Done.