Section 2.4: Evaluation approaches
Evaluating text alternatives
To determine if your site complies with accessibility guidelines, you may need to evaluate whether your site provides appropriate text alternatives for the images on your site.
Evaluation Issues for Alternative Text
For each image on the page, you should ask:
- Is the ALT attribute present? (even if the ALT is set to null)
- Does the text alternative serve the same purpose or provide the same information as the non-text content?
- Is an additional description necessary?
Tools for Evaluating Alt Text
There are tools that can be used to identify images and ALT text but the appropriateness of the text and the need and appropriateness of additional description will require your judgement.
You can do either of the following:
- Change your browser settings (you can change them back) to turn off images. There are several ways to turn off images, depending on what browser you use. Read how to change your browser settings.
- Or if you use Internet Explorer, Download and install the Accessibility Toolbar at www.visionaustralia.org.au/ais/toolbar. Read toolbar set-up directions.
This toolbar offers some different options for checking images.
- There is a button called Images. From the choices in the Images menu, you can select toggle images/alt.
- There is a button called Tools. From the choices in the Tools menu, you can select The Wave. It gives a graphical representation of where the images are on a page.
Activity 4: Evaluate text alternatives for a Web page
Questions 1-4
Review the Research page of the Harry Ransom Center at Harry
Ransom Center
Most of the images are links for the navigation. The orange line under the Harry Ransom title is decorative. The Mark Twain image is probably subject to the content developer's interpretation. It could be seen as decorative since the page is not about Mark Twain or the image could be seen as part of the content because it is representative of one of the items in the Harry Ransom Center collection.
The ALT text seems appropriate for the role of each image. One possible change: the HRC logo at the bottom of the page is also a link to the home page and the ALT text should probably reflect that.
Questions 5-8
Review the Smithsonian Institute Geographic Resources page at Smithsonian
Institute Geographic Resources
The map in the center and navigation at the top make up the majority of the images and are links that take the user into the site.
- The spacer images should have empty ALT (alt="").
- The images in the center should have ALT text that includes the text that is in the graphic "Geographic Resources from the Smithsonian. Explore rich online resources created by Smithsonian experts for learning more about our world!
- The logo link at the bottom left of the page should have ALT "Smithsonian Education home".
- The logo link at the bottom right should have ALT "My Wonderful World home"
Points to take away
- Text alternatives are integral to design
- Text alternatives are content
- Accessibility standards are tools, not just rules
