Author: Janice Florent

by Janice Florent

The fourth tip in my series of accessibility related blog posts will focus on alternative text (alt text). Computers can read text on a screen but images, graphs, and charts are meaningless to visually impaired users. Alt text is an alternate method for supplying information about images to users who are visually impaired.

Alt text is important for screen reader users because a screen reader cannot describe an image. Since screen reader software cannot interpret images, it relies on alt text to communicate image information to the user. When an image does not have alt text the only information the screen reader can relay is that there is an image on the page and provide the file name for the image.

Alt text should describe an image so it makes sense in context. If a picture is worth a thousand words, then a short alt text description may be a poor substitute. While a concise alt text description is important, the alt text should be less than 125 characters. You want to think about what is the most important information you are trying to get across with the image and stay within the 124 or less characters. If the image requires a lengthy description, you should describe the image in the content of the page.

There are several ways to handle complex images (e.g. charts, data, statistics, etc.) where a short description is not possible. The best solution is to include a thorough description of the complex image in the content of the page, immediately before or after the image. If you don't want to add more content to your page, another preferred alternative would be to create another web page with just a description of the complex image and link to it near the image. Additionally, text descriptions of graphs and charts can help all students understand difficult concepts.

How alt text is written will vary depending on the type of image. Most screen reader software announces the presence of an image by appending a word such as "graphic" to the alt text, so using words such as "image" "graphic" and "photo" are unnecessary in the alt text, unless it helps to convey further meaning important for a user to know.

Consider this example which uses “Guide Dog and Man” as the alt text:

The alt text “Guide Dog and Man” is not effective if the intent is to show the dynamic action of guiding in the picture. In this situation a better alt text description is “A guide dog leads the way with her handler holding the guide harness in his left hand” as shown in the following example:

There is no need to include "image of," "picture of," or "photo of" in the alt text in this example because the screen reader will announce the presence of the image.

Additionally, images that contain text (as in a logo) should generally be coded to just include that text as the alt text.

Many images are used only for visual interest, they aren't meant to convey any meaning or important information. In this case, it is best to use what is called NULL alt text or empty alt text. This is done by entering two quotes ("") with no spaces in between in the alt text box.

So, how can you add alt text to images? Listed below are instructions on adding alt text in MS Word and PowerPoint documents as well as in Blackboard.

Add Alt Text to image in MS Word and PowerPoint 2010:

1. PC users: right-click on an image
   Mac users: press control key and click on the image
2. Select Format Picture
3. Select the option for Alt Text
4. Type your alt text in the description field
5. PC users: Click Close
   Mac users: click OK

Add Alt Text to image in Blackboard:

You will find the Alt Text box in various places in Blackboard depending on what and where you are adding the image. Here are some examples:

1. Create Image in Bulid Content:

2. Insert image in the Content Editor:

You will remove significant barriers for the visually impaired if you take these suggestions for adding alt text into consideration when creating course content. An added bonus is that if you take the extra step to include alt text when creating your course content you will be ahead of the game in the event you do have a visually impaired student.

Additional information about alt text can be found at:

• WebAIM Alternative Text
• SSA Alternate Text for Images Guide (PDF)
• Describing Complex Images

Image credit:
"Students of the Educational Institute for the blind show how to use a computer as a learning aid" by Paul Kagame is licensed under CC BY-NC-ND 2.0

by Janice Florent

The third tip in my series of accessibility related blog posts will focus on descriptive links.

Links are like sign posts. They should tell you what you will find when you follow them. When using a computer, people are generally skimming pages for links. They tend to skim pages to quickly find what they are looking for.

Text links on a page are easily identifiable to persons who are not visually impaired because they are normally colored and underlined, and therefore stand out from the other information on the page.

Persons with a visual impairment using screen reader software are presented with a “links list” with all the available links found on the page. Screen reader users and persons using text-to-speech browsers often navigate websites going from link to link using the tab key, so providing descriptive links is extremely important.

Link text stands out in the same way that bold text does. If all your links have non-descriptive link text like "click here" or "more information" users are forced to read the text around the link to understand the context of the link and where it will take them. Therefore "click here" and “more information” are more of a hindrance than a help.

For effective skimming, both visual and non-visual users benefit from link text that can stand on its own without the surrounding context of the page. Good link text provides a clear description of the page that will load when following a link. With good descriptive link text, users can skim links and make quick informed decisions about the path to take to accomplish their task. With non-descriptive link text, users cannot ascertain where the link will take them from the link text alone. Therefore, you should avoid non-descriptive link text such as:

• Click here
• Here
• More information
• Read more
• Continue

These types of non-descriptive link text offer no explanation and require users to expand their focus to the surrounding context or follow the link to discover its destination.

Consider this example of a list of all the links on a page that a visually impaired user has pulled up for quick access.

As you can see, the list of "click here" links is meaningless. Descriptive links as shown in the image below are far more useful.

When choosing descriptive links the link text needs to be long enough to convey the purpose of the link and no longer. Make link text clear and self-explanatory to support quick and effective navigation.

When scanning links, the first words in the link text are the ones most likely to grab the user’s attention. Link text that begins with keywords is easier to scan efficiently and works better with software features like "link lists" that visually impaired individuals use to get an alphabetized list of links on a page.

Links beginning with non-descriptive words are not very helpful. Consider these two examples "All about ocean acidification" and "Learn more about global warming." Scanning these links will be slower and the alphabetized links list is not going to be very useful. A better approach is to use only the keywords for link text. For example those two links could be improved if they were formatted as "All about ocean acidification" and "Learn more about global warming."

Some users make links out of entire sentences or entire paragraphs. These long links are probably unnecessary and are not user-friendly for screen reader users. Remember that screen reader users cannot visually scan through lengthy links. They have to listen to the entire text. Some screen reader users get frustrated with long link text and move on to the next link if they cannot understand the purpose of the link after the first few words.

URLs are not always human-readable or screen reader friendly and therefore using URLs as link text should usually be avoided. Exceptions are when the document is intended to be printed or if the URL is relevant content.

In most cases, it is better to use human-readable text instead of the URL. The human-readable link Pocket Guide to Colour Accessibility is more user-friendly than the link to purchase the ebook by the same title on Amazon.com, which consists of this 131-character link full of letters, numbers, slashes, and text that is not very human-readable (http://www.amazon.com/Pocket-Guide-Colour-Accessibility-ebook/dp/B00EPJBN30/ref=sr_1_1?s=digital-text&ie=UTF8&qid=1439306713&sr=1-1.)

Additionally, links don't always lead to web pages. It is equally important to make this clear in your link text. Users appreciate knowing in advance, for example, that if they click on a link on their mobile device they will download a 20Mb PDF. In this case, the link text should indicate that it is a link to a file, including type and size of the file. Here's an example: Getting Started with Assignments (PDF, 20MB).

Writing good link text isn't difficult. If you take these tips for creating descriptive links into consideration when creating course content, you will remove significant barriers for the visually impaired. An added bonus is that there will be students without disabilities, as well as those who have chosen not to disclose their disability to you who will find your use of these tips helpful as well.

If you are interested in getting more information about descriptive links refer to “Link Text” at webaim.org.