Assessing OER for Accessibility

by Christine Scherer

Open Educational Resources (OERs) are often praised for being more accessible than standard textbooks. In this context, accessibility often refers to low or no costs, or to how students can obtain the resource just by clicking a link. But accessibility also has another meaning: can disabled people access the resource? And in this sense, OERs are no better than the competition.

According to UDL on Campus, a 2011 survey of OER textbooks found that nearly half the web-based textbooks (42%) had significant accessibility problems. And of the PDF textbooks, none were accessible to disabled users.

This is a tremendous concern. Here at Northwestern, there are over 1400 students registered with AccessibleNU, our disability resource center. The number of students registered increases by about 11% each year, and there are very likely many more students who haven’t registered and are getting by as best they can without accommodations. These students will face delays, frustrations, and avoidable stress if they encounter an OER that they can’t access. 

There is also a legal component: a majority of higher education institutions, Northwestern included, are required to comply with a variety of federal laws and statues around web accessibility. These regulations say that all course materials must be accessible to disabled students. Failing to provide accessible materials can open the institution up to legal action. 

Web accessibility is critically important for a variety of reasons, which you can read about in more detail at the linked blog post. So how can you ensure that your OERs are accessible? Follow these steps, and you’ll be well on your way.

1. Look for a VPAT

A VPAT, or a Voluntary Product Accessibility Template, is a form that technology creators and vendors can fill out to assess and report on the accessibility of their product. The form asks for detailed information about a wide variety of accessibility supports and features, some of which we’ll talk about next. It’s always a good idea to reach out to an OER creator and ask if they have a VPAT, or any kind of accessibility statement. If they do, that’s great! See what they’ve talked about, which standards they’ve hit and which ones they’re still working on.

However, if you reach out and get no accessibility information, or get a response that talks only about vague, future plans for accessibility, that’s a red flag. It’s time to do some testing and investigating of your own.

2. Automated Checkers

We’re going to talk about hands-on tests you can do, but if that seems intimidating or overwhelming, there are a number of fairly reliable automated checkers you can use as a starting point. The report from an automated checker can highlight some problem areas very quickly. But don’t take an automated accessibility checker as the final word! There are lots of things that a computer will miss, and you’ll need to do some digging on your own.

PDFs: Adobe Acrobat Pro DC has a very robust accessibility checker built in.

Office Suite Files: The Microsoft Suite also has accessibility checkers built into their software. Open source office suites, like LibreOffice, are less consistent in the availability and accuracy of their accessibility checkers.

Websites: For web-based content, there are numerous web accessibility checkers available online. I especially like WebAIM’s WAVE checker, which is available both as a website (that can scan one page at a time) or as a browser extension (that can scan an entire site).

3. Keyboard Navigation and Screen Reader Usability

This can be the most intimidating part of accessibility testing! But at this point, you really only need to do a very basic level of testing to get a feel for the accessibility of the resource. Take your hand off the mouse and, using the Tab and arrow keys, try to navigate through the resource. Can you access everything? Can you tell where your cursor is on the page? Any elements that you can’t get to with a keyboard will be inaccessible for lots of users, including blind or low-vision users, or users with physical disabilities that prevent them from using a mouse.

If you want, you can also see how a screen reader interacts with the resource. MacOS users have VoiceOver built in and can activate that; Windows users may need to download an external tool like NVDA to test it out. Is everything on the screen read aloud clearly? Are things mislabeled, or skipped entirely? Listen carefully for things that don’t match what’s on the screen.

Note: Just because you have difficulty navigating with a keyboard or a screen reader doesn’t mean that there are actually problems! Both are tools that require practice and skill to use well. Novices may struggle, but that doesn’t mean that problems actually exist. When in doubt, reach out to the creator to ask about these specific areas, or investigate options for having expert screen reader users test the products.

4. Text Alternatives

Screen readers can’t “see” images to describe them to blind or low-vision users. Deaf and hard-of-hearing users generally can’t hear audio tracks well enough to follow along. For images, audio, and video, text alternatives must be provided. These text alternatives are better known as alt text or image descriptions, transcripts, and captions. Check to see if your OER provides these alternatives, or if it provides places for you to input your own.

You can read more about how each of these work at the resources below.

Alt Text/Image Description

Captions & Transcripts

Important note: auto-generated captions or transcripts are never acceptable. They can be a good starting point, but on average, most are only 60-70% accurate. Imagine how hard it would be to follow a conversation if one in three words was wrong! You can create an auto-generated transcript or caption file, but you must do the work to listen and edit it to 99% accuracy.

5. Color and Contrast

Color is a great way to communicate and draw attention. But for students who are blind, low vision, or colorblind, color-coded information is often inaccessible. A student who is red/green colorblind, for instance, will struggle to find keywords that are written in red. This excellent blog post can help you understand the many challenges that color can pose. Color can still be used, of course! But it can’t be the only method of conveying information. Combine color with text, texture, pattern, weight, etc. in order to make sure that students who can’t see the colors can still understand the message.

Similarly, it’s important to make sure that any colors used have a high level of contrast. The blog post talks about this as well, but in short, many users need very high contrast in order to clearly read text. Black text on a white background, or white or yellow text on a black background, have very high degrees of contrast. Tools like WebAIM’s Color Contrast Checker or The Paciello Group’s Color Contrast Analyzer are both great ways to make sure that an OER has high contrast.

6. Formatting

This will be caught by most automated checkers, but it’s important to be aware of. Headings, lists, and tables all must be properly formatted in order to be accessible. That means using heading tags like H1, H2, etc. in proper descending order, as well as appropriate tags for ordered and unordered lists. Using bold, underline, or italics to create headers makes navigation really difficult for screen readers. Likewise, tables should be used for the presentation of data only, not for layout and style, and they must also have appropriate tags for header rows. This page about formatting on the SPS Distance Learning website goes into a bit more detail.

Next Steps and Further Reading

By keeping these elements in mind, you can ensure that any OERs you select for your course are not just accessible from a financial or speed perspective. You’ll provide resources that are accessible to disabled students, no matter what tools they use to access your course.

If you’d like to continue learning about accessibility, here are some great resources and training opportunities!

  • Northwestern Accessibility Hub: a central resource for all things accessibility, both physical and digital, at Northwestern.
  • AccessibleNU: Northwestern’s disability resource center, providing support for students and training opportunities for faculty and staff.
  • SPS Distance Learning Accessibility: information about creating an accessible online course at Northwestern.
    • SPS Distance Learning will be offering a pair of workshops on accessibility and UDL this spring. If you’re interested, please contact Christine Scherer at
  • NUIT Canvas Accessibility training: in-person training opportunities on accessibility in Canvas.
  • WebAIM: a web accessibility resource for a broad, non-technical audience, providing excellent introductory information for those looking to learn more.