Overlap of digital accessibility and plain language

Good morning,

After spending the last year looking at the potential overlap of plain
language and digital accessibility, I do believe I found some information
that may be of interest to the WCAG 3.0 editors.

I have attached my master's thesis as it serves as the backbone of what
information is to follow, but after looking at the principles, guidelines
and success criteria of the WCAG 2.2 in comparison to the draft version of
Plain Language ISO 24495-1:2022 (PL ISO), I found some information relevant
to what I believe to be the forward movement of accessibility.

*Snippets of my thesis that are most relevant:*

Readability is different from comprehensibility and also at the root of a
detrimental difference in mindset found between the WCAG 2.2 and the PL ISO
whose standards are both trying to fulfill the goal of “understandable”
content.

Currently the WCAG 2.2 appears to be relying more so on readability than
comprehensibility in its quest for fair and equitable digital information,
leaving users without the right tools for true access.

According to my research, for the WCAG 2.2, the guidelines and success
criteria for the principle of “Understandable,” (focusing primarily on the
guideline of “Readable”) short of success criteria 3.1.5, “Reading
Level,” *relate
more to specific, individual components of the text, and not the text as a
whole* (WCAG 2.2 “Readable” success criteria: “Language of the Page”
(3.1.1), “Language of the Parts” (3.1.2), “Unusual Words” (3.1.3),
“Abbreviations” (3.1.4), and “Pronunciation” (3.1.6)). These success
criteria are primarily associated with individual components of a text.

In opposition, is the PL ISO’s principle of “Understandable,” which has
more to do with overall comprehension of the text. The first part of PL
ISO’s principle 3, “Understandable,” is 5.3.1 “Overview,” which states
that, “Individual elements of a document, such as wording and structure,
should be easy to understand. These individual elements should work
together so that readers comprehend the document as a cohesive whole” (PL
ISO, 2022, p. 6).

Relying mainly on reading level and individual textual components is in
opposition to the current practices in place that factor in
comprehensibility (or the true “access”) in regards to digital
accessibility, thus defying the idea that the information, if readable, is
usable. Suffice it to say, it is still progress to focus on readability in
regards to digital content, but by focusing on readability alone, it fails
to fully aid in the UNCRPD’s “environmental barriers” being dissolved -- in
this case, on a conceptual, intangible level.

The use of plain language is one way to help dissolve the barrier that
comprehensibility can create, but its use must be a choice, and one that
currently involves extra time and training.

Additionally, most of the success criteria related to the WCAG 2.2,
principle 3, guideline 3.1, “Readable,” that overlap with guidelines from
the PL ISO (and thus comprehensibility), are labeled with a rating of “AAA”
which means that they are suggested, but optional. This means that although
structurally in the WCAG 2.2 there is a separate principle for the digital
material being understandable, it is not as weighty as perhaps some of the
other WCAG 2.2 principles.

This then begs the question that if the reader can’t access the information
in regards to comprehensibility, then what is the value in the rest of the
guidelines? If there is ALT text present but they can’t comprehend its
meaning, then is this really access? If a reader can get to a website that
functions well with their screen reader but can't understand the critical
health information on the page, shouldn't this be considered just as
important as those elements that fall under "A" or "AA"?

I am honored to have shared a bit of my findings with you, and commend you
on all the effort you are putting into making this world more accessible.
Should you have further questions or comments, I would be honored to answer.

Kind regards,
Ashley Miller