Alternative Text for Images

(UFIT logo is visible before fading from the screen. The narrator faces the camera)
Welcome to Accessibility in 5, a series from UFIT where we explore a quick tip on making your content more accessible in five minutes or less.
(Lower third reads Laura Jervis, instructional designer)
I'm Laura, and today I'm going to give you a crash course in creating alternative text for images.
Alternative text (or alt text) is a brief description of an image that conveys the purpose of a visual on a website, document, or PowerPoint.
But why is alternative text necessary? If you're sighted, like me, and you're learning something new by, say, watching a presentation or looking at a website, you can probably glance at a picture and very quickly learn something about the content that you would otherwise miss. Alternative text is metadata that content creators attach to images to provide that content to users who can't see them. 
Someone who's blind or visually impaired may rely on a screen reader to navigate websites and documents. This software reads the screen out loud and allows users to navigate via keyboard commands.
A screen reader cannot automatically interpret images, so alternative text allows the software to provide an equivalent experience. In some browsers, alt text will be displayed if an image cannot load, so it might also be useful for people with a slow Internet connection.
The specifics of how you add alt text vary by document type, but you should be able to find tutorials online using alt text plus the software name as a search term.
The real challenge with alt text is figuring out what exactly to write. Since the purpose is providing an alternative means of access to the image, you should start by asking yourself what you see when you look at it. Then ask yourself why you included the image to begin with. How does it illustrate the content? What's important about it? What's it demonstrating? Then you can describe the image with the purpose of it in mind.
Alternative text should be concise. You don't need to repeat things that are already in the accompanying text, and you should keep it to one or two sentences. But be sure to include key information such as what it is and how it relates, so someone can understand its purpose without seeing the image.
You also don't need to say "image of" or "picture of" because the screen reader can already identify that it is an image. The exception to this is when the format is relevant, such as if you're using a screenshot as part of a tutorial
on how to use a type of software.
If there is text in an image, you likely need to repeat or summarize it in the alternative text.
Now sometimes we add images to content just to look pretty, break up the text and add visual interest. In this case, you can mark an image as decorative. This means a screen reader will not acknowledge the image, which will prevent a user from wasting time listening to an unnecessary description.
Let's take a look at an example of how to write alt text. 
(Image of Chauvet Cave paintings horse panel is visible on screen) 
This is the horse panel from Chauvet Cave in France, which was painted about 36,000 years ago. 
If I included this in a PowerPoint presentation about the domestication of animals in human prehistory, the alt text might be something like: Chauvet cave paintings from the Paleolithic era depicting wild horses with stocky necks and coloration that ranges from dark to light.
However, that same alt text for the same picture would not be as appropriate in another context. If my PowerPoint were about art history, I might write alt text that says: Chauvet cave paintings depict four horses in profile, drawn in charcoal and ochre; the underside of the jaws are shaded to create depth.
Furthermore, if I were talking more generally about art and human creativity, and I only included this image as an example of something pretty that humans have made, I would probably not write alternative text at all and would simply mark it as decorative.
Some programs automatically generate alternative text for you. I do not recommend using it without editing it carefully because it's frequently unhelpful or downright inaccurate. In fact, when I inserted this same image of the cave paintings into Microsoft Word, the auto-generated alt text was: A picture containing text, mammal.
If you would like help practicing writing quality alternative text, I encourage you to reach out to UFIT's Center for Instructional Technology and Training for a consultation by going to citt.ufl.edu and clicking on Request Help.
(CITT website is on the screen. The Request Assistance button is shown on the top right.)
I would love to help you describe some images.
Thanks for watching Accessibility in 5. You can find this video, as well as previous ones, archived under Resources on citt.ufl.edu. Tune in next month to learn more about captions and transcripts. 
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