Module 1 Book: Formatting Course Content so it's Accessible

Images

According to the Principles of Multimedia Learning, people learn better from a combination of words and images than words alone (Mayer, 2009). To ensure that your content is accessible, it is important that images in your content can be interpreted by all learners. The UDL guideline for providing options for perception recommend presenting content in a way that doesn’t depend on a single sense, such as sight, by providing alternative ways of interpreting information or ways for learners to customize how information is displayed. 

Using images to convey information can negatively impact a variety of learners if accessible practices are not included. The most obvious learners who may be impacted are those who are blind, have poor contrast vision, or cannot differentiate certain colours, but learners who rely on monochrome displays, printing content, have poor internet access, or have cognitive disabilities can also be impacted.

If your course content includes images, such as graphs, diagrams, or illustrations, you should first ask whether the images are decorative or serve a functional purpose. Decorative images are, you guessed it, for decorative or design purposes only. These may include banner images or groan-inducing memes. Decorative images are not necessarily a bad thing – they can be aesthetically pleasing or humorous - but they should be limited. Functional images are those that convey non-text information to students.

Once you determine whether the image is decorative or functional, decide how you will meet the accessibility needs of your students.

If your image is decorative, it may not necessarily need descriptive text. The alt text can read something like “decorative image” or be a brief description. You do not want to overload the learner with unnecessary information, but you also don’t want to leave the alt text blank, as a screen reader may read out the image URL instead.

If your image is functional, there are two primary accessibility considerations: the use of colour and the inclusion of descriptive text as an alternative way to convey information.

Images should not rely solely on colour to convey information, as information may be lost for learners who are not able to view the image or perceive the differences in colour. The easiest question to ask yourself when determining whether the colour in your image is accessible is, “Would learners still be able to perceive the information if the image was in black and white?” Strategies like using high contrast colours and adding additional context via text can help your colour images be more accessible. You will learn more about accessible practices surrounding the use of colour below.

Descriptive text provides a text description of an image should it not load or if it is being interpreted by a screen reader. It should describe what is being displayed and why it is important.

Following are three methods for adding descriptive text to functional images for students who may not be able to view them:

The figure below demonstrates providing relatively long text descriptions of a diagram in both a paragraph and list format. Which is easier to interpret?

Brain Diagram with Accompanying Text Description in Paragraph Form (top) and List Form (bottom)

Adapted from Amornchat, Supada (n.d). Complex Images for All Learners. Licensed under CC BY-NC-SA 4.0. pcc.edu/accss.

The following tips will help you write effective descriptive text:

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