[BlindMath] long descriptions of mathematical images

Nikita nikitamailings at yandex.com
Sat Jul 9 11:43:20 UTC 2022

Hi Alex.
For long descriptions of images, it is better to use special semantic tags
<figure> and <figcaption>
For example:

<figure aria-labelledby="img1">
<img id="img1" alt="Short description">
<p>Long description.</p>

The content of the <figcaption> element can be visually hidden or made into
an expandable spoiler, as in your prototype.
Sincerely, Nikita.

-----Original Message-----
From: BlindMath <blindmath-bounces at nfbnet.org> On Behalf Of Alex Jordan via
Sent: Saturday, July 09, 2022 3:26 AM
To: Blind Math list for those interested in mathematics
<blindmath at nfbnet.org>
Cc: Alex Jordan <alex.jordan at pcc.edu>
Subject: [BlindMath] long descriptions of mathematical images


I contribute to some open source projects in math education. A
challenge with images on the web in the context of math education is
how to describe them for screen reader users. The normal advice for
alt text does not always apply, since you often would like the reader
to extract something from the image without directly telling them what
they are supposed to get out of it. And if alt text becomes too long,
then some screen readers cut it off at 100 characters or so.

I wanted to ask this community if you know of good strategies for this

I also want to ask for criticism of a method I am experimenting with.
In this method, I follow the image with an HTML details tag with a
summary tag. The img alt text asks you to read the longer description
in the details tag. There is an aria-describedby that references the
div within the details tag where the description lives. Here is a toy


May I ask this community, in particular blind AT users, for feedback?
If you follow that link, what criticism/commentary/observations do you
have about this method for describing an image? Please forgive me if
the description itself is poorly written.

Thank you,

Alex Jordan
Mathematics Instructor
Portland Community College

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