Hi, I have a suggestion that could be applied to most content on the website. I think that Khan Academy could expand its reach to blind students, and this would be easy to do. Part of the content is already kind of accessible to blind people: the student can either use a text to voice program, or, if needed, convert the text to Braille and use a Braille printer. But still, there are features that are inaccessible, like, for example, a plot for enzyme versus substrate reaction rate. An easy solution, still not available on the website, would be figures especially designed for the blind. These figures would then be opened by software like Cura, and printed with a 3D printer. I have prepared an example that I uploaded to this wikipedia page:

https://en.wikipedia.org/wiki/Phylogenetic_tree

I am new here but I believe that Khan Academy is better structured than Wikipedia. What I have in mind is: I want to be available to prepare this blind-friendly figures to anyone who requests. I can also post some guidelines (in fact, I am doing this at the end of this message) to prepare such figures, based solely on my experience with 3D printers.

In short, I suggest that most pages with line, bar, scatter, plots, etc, also provide a version for the blind. We could even categorize the pages with these extra figures as "blind friendly", so that when someone search for this content she will find it.

I believe there are huge applications for this suggestion, and I am open to other related suggestions. 3D printing is a disrupting technology which must be embraced for the classroom.

Best,

Matheus

Quick guidelines for blind-friendly plots:

1) They must be grey scale, and, in some cases, black and white

2) Lines must be thick, and well spaced between them.

3) The figure should be low resolution (max 500 x 500 pixels)

4) Braille descriptors should be used

5) Grid lines should be used

Example:

Some of these suggestions are for small 3D printers. Bigger (and more expensive) printers should be able to print larger objects that are still coarse enough for understanding by touch.

This list is incomplete as I have just started playing with the idea.