Writing effective alternative text

Including images in your content can enhance student understanding, convey complex information, and improve retention (Mayer, 2009). Images included in learning content should be purposeful, aligned, and accessible. Information about using images effectively to support learning is available in the Adding images to a subject site article.

To ensure all students can access the content conveyed in images, an alternate format should be made available. Alternative text (alt text) is a descriptive text substitute for an image that outlines the purpose and meaning to the reader. The image description is read by screen readers and other assistive technologies; and is available if an image fails to load.

Why?

The Web Content Accessibility Guidelines (WCAG3) outline a set of requirements for making content accessible for everyone. Providing alt text for images ensures that all students have equal access to information and learning experiences. It is particularly beneficial for screen reader users and those experiencing slow internet speeds (Web Accessibility Initiative, 2022).

How?

When adding an image via the text editor, you will be prompted to describe this image for someone who cannot see it. This will then be used as the alt text for the image. This should be provided for all images, including complex images, icons and QR codes.

Detailed instructions for adding image descriptions in Moodle are available in the Adding images to a subject site article.

Guidance on writing effective alt text, including specifics for different image types, is located below. Click on the headings to expand/collapse the sections.

 

If an image contains text, describe both the illustration and the text clearly and separately. This ensures each component is accessible to the reader.

For example, Accessible Publishing provides the follwing example:

Alt-text: 9 scoops of ice cream pictured in a 3×3 grid. Title: You can only choose one. From top row, left to right: vanilla, chocolate, strawberry; mint chocolate chip, cookie dough, cookies & cream; butter pecan, rocky road, pralines & cream.

References