Andreas Stefik (who discusses what we know about the usability of programming languages in this entertaining podcast) has worked extensively on computing education and programming tools for the visually impaired. When asked earlier this week how to teach programming to the blind, he sent the response below. We’re grateful for his comments, and for Evan Williamson’s recent pull request to improve the accessibility of our lessons.
If you are making any presentations, be sure to provide the powerpoints to the blind individual in advance if you can. Powerpoint is the “most” accessible, but if you have any images, you need to manually specify “alts” inside the presentation. It’s not hard, but most people don’t realize powerpoint has this feature.
When actually presenting material, for any kind of diagrams, I find it helpful (if my audience is blind) to practice oral description of the images ahead of time. This is sometimes tricky in code, especially for things like linked structures or trees. So, if you are explaining those kinds of concepts, just be aware that it might take some practice. I’ve practiced this for years in my own presentations, but still find it challenging sometimes for highly visual content (e.g., we taught 3D gaming to blind people this summer, which was a real challenge).
Same goes with code. If the person doesn’t read code coming in, screen readers don’t even output all of the special characters without special modes turned on (e.g., verbosity mode in JAWS). For example, if I have:
a = a - b
it might say “a equals a b” (notice the missing minus). Point being, depending on the experience level of the person coming in, and how comfortable they are with their screen reader, they might need some help getting used to the quirks. When presenting, you sometimes have to actually say the special characters or they won’t know they need to be typed.
If you are using tools for programming, a great many out there don’t work for the blind. The best you can do here is make sure you get them to the person in advance if you know they work. If you don’t, you can either ask or at least have a fallback. A basic text editor and the console usually works on most systems, although that doesn’t mean that kind of setup is easy to use. We have some stuff that might help, but it depends on what you are teaching and your specific needs.
Different languages can cause major issues for blind individuals. I could go into detail, but imagine things like white space in Python. Or, imagine hearing statements like, “for left paren int i equals semicolon i less than ten semicolon i plus plus right paren left brace” in C. Both can cause headaches for various reasons.
Find out about their specific needs beforehand if you can and if they are willing to tell you. If they just need magnification and large print materials, this stuff is a lot easier. If they are a total, then braille can be helpful. But, crucially, you need to know whether they know Braille, and if so, which kind. Braille standards have changed in recent years and it matters for computer code because of the special characters. I’m not a Braille expert, but if this is an issue on your end, I can get you info from some experts.
Finally, one thing I almost always recommend to do before hand, just to make sure you have a little bit of context, is to download a screen reader and give it a shot. On Windows, grab NVDA, or on Mac, just press APPLE F5. Even spending an hour going over a tutorial can help give you a little of context. Spending an hour programming blind on your own won’t make you an expert, but it’s such a different way of programming that it might help give a glimpse into that world.
This post originally appeared in the Software Carpentry blog.