After procurement of accessible technology, school districts and institutions of higher education are responsible for ensuring any digital content provided to students or content posted to websites are fully accessible. The same principles applied to web-based software under principles 1, 2, and 3 should be applied to purchased content from publishers. For content posted to websites by users—i.e. staff, faculty, and educators of a district or institution—having a policy for posting content can help to avoid common mistakes, such as pictures without alternative text descriptions, mislabeled files, inaccessible PDFs, or improperly cited URLs.
Use Accessibility Verification Tools Whenever Available.
Some vendors whose tools allow for content creation, such as learning management systems and web site development tools, include an accessibility “checker” in their platform. Much like a spell checker, these tools can scan through content and images prior to publishing to help identify where accessibility problems exist and suggest how they could be resolved. For those times when a built-in tool is unavailable, there are many free websites available that can scan a webpage for likely errors. A list of web accessibility checkers can be found on the W3C Web Accessibility Initiative website..
Of course, machine testing cannot be relied on for 100 percent accuracy. Human judgement is essential at some levels. Just as incorrect words might escape spell check, inaccessible content may escape an accessibility checker. For example, an image with an alternative description of “picture” will be able to pass a checker tool despite not having a meaningful description for a user with visual impairments.
Require Meaningful Descriptions for Pictures, Buttons, and URLs.
Alt tags, or alternative descriptions, are a frequently missed item in user generated content. For users with visual impairments, this can make following content, completing assignments, or just understanding what their sighted peers are experiencing impossible. Alt tags and descriptions must be meaningful as well. Labeling an image as “picture” does not provide a student with an equivalent experience if a sighted student is looking at an image of a snowy field at dusk with a barn in the distance.
An image’s alternative text must convey not only a description of the image but the meaning of the image within the context of its surroundings. The same image may require different alternative text depending on when and where it appears in content. WebAim.org has a helpful guide to image alternative text and examples.
Buttons, including images acting as buttons or links, should be individually labeled to give context to where it will lead users. URLs should describe where a user will go rather than simply “click here for more.”
Avoid PDFs and Images of Text Whenever Possible.
Whenever possible, text content provided to students online should be embedded in the body of a webpage as HTML or otherwise provided in a format that is easily rendered by assistive technologies, such as screen readers. Downloadable file formats, such as PDFs, too often are inaccessible for many individuals using assistive technology or who require search capabilities to locate content.
Often the default file format for open education resources and readily available on the internet, PDF content is one of the most inaccessible forms of content distribution. Due to the various ways in which content is converted into and stored in the PDF format, the original content flow and hierarchies often become out of sync for assistive technologies or do not even make it into the PDF.
Images containing text are a close second behind PDFs as an inaccessible form of content distribution. Even with a meaningful description of the image and the text, the content can be out of sync with the remainder of the page and leave an individual with a disability without the surrounding context and/or lost on the web page. All text, especially text conveying meaning or instruction, should be included in the body of a webpage as HTML. Charts and graphs in STEM disciplines can be special exceptions to this “text in an image” rule. For guidelines on describing STEM images, visit the National Center for Accessible Media’s “Guidelines for Describing STEM Images.”
If posting content in a separate file (i.e. not in the body of the page as HTML) is necessary, content developers should consider file formats that are conducive to assistive technologies and re-editing, such as Microsoft Word documents.