Open Myndex opened 11 months ago
This is copypasta from Defining Requirements for a Complete Visual Contrast Guideline #103.
Comments and thoughts welcome.
#76
to #a3
), WCAG 2 is incorrect in determining when to flip from black to white text.
For mixed case writing systems only:
For most writing systems:
Font weights 100 to 900 defined with standard reference font.¹
Provides design flexibility by dividing readability into appropriate use cases²
Technology for zooming, reflow
Zoom examples in practice. For the following examples, let's assume that our default size body text is 16px Verdana, and we have a 36px headline in Barlow. Then let's compare a regular desktop screen and a mobile phone in portrait mode, the two extremes of display device size.
16px
font becomes 80px
, which accommodates 20/100.Encompass non-text contrast and design guidelines in a complementary manner.
1) A CSS property to directly set font size by x-height.
The list looks long, but this list is more about process, the actual guideline(s) should have much of this "hidden" and simplified for ease of use by designers and testers.
FOOTNOTES
1) Ideally a custom primary reference font is created, with variable weight for at least 300 thru 700, and including 100,200,800,900 at least as individual weights. Primary reference to have a 0.5 x-height ratio, and aspect, letter and line spacing to be consistent with best practices for body text.
2) Appropriate use-case definitions is the appropriate design-friendly way to deal with what WCAG2 called "three way contrast". Not only does WCAG 2 contrast fail for not actually being 3-way, it is trying to solve design use-case definitions without any consideration of use cases.
Copyright © 2021 to 2023 by Somers & MTI. All Rights Reserved.
GitHub user xi did an analysis of APCA, which he linked to in Silver issue #651.
There are a number of significant concerns regarding the nature and content of his analysis. To set the record straight and respond with corrections and brief discussion, I've created the following repo, the corrected APCA Introduction, which clearly breaks the issues down and directly addresses any misunderstandings.
Thank you for reading.
APCA Review Status
Per the Contrast Subgroup:
Our understanding is that peer review is not a part of the charter, and that no other subgroup for WCAG 3 has been required to seek out peer review. Nevertheless the Visual Contrast group has proactively compiled a listing of independent peer and other reviews. APCA and related guidelines have been developed in the open, starting with thread wcag #695, and have been in open public beta testing since the stable February 2021 release (nearly three years of beta testing).
In 2020 we suggested setting up a panel of experts from relevant fields, as is done at standards groups such as SMPTE or ISO. Such a process would help support future legislative efforts. It is this author's opinion that AGWG and WCAG would only be strengthened by developing a professional independent committee/panel process, as used in other standards organizations.
A Solid Foundation of Science
It is important to again point out that the APCA Readability Criterion guidelines are derived directly from the peer-reviewed scientific consensus in readability research, and the APCA formula rests on decades of well established vision science and the latest advances in peer reviewed color appearance modeling.
We are aware that some individuals have made derisive statements to the contrary, but their uninformed demurrers have no factual basis and are notwithstanding — such spurious statements are an affront to the many a11y advocates, members, study participants, beta testers, and developers who have been working with all due diligence over the last 4 2/3 years of research, development, and/or testing of these methods.
Independent Peer Reviews of APCA & More
The following is a collection of journal published peer reviews, independent peer reviews, public reviews, and including reviews by PhDs, vision scientists, corporate stakeholders, developers, designers, and engineers. Several reviews include demonstrations of the functional superiority to existing methods. The first few listed below are technical reviews by peers evaluating the APCA math and methods. Some look into the internals, functioning, or the usability and practicality of APCA.
APCA Featured in Print
Reviews of WCAG 2 Contrast
Discussion with links to third party articles
written prior to the development of APCA
The problems of 4.5:1 as a target for a guideline is that it not only impact those with impairments, but impacts standard vision as well. WCAG 2 contrast SCs affect 100% of sighted users. The inherent problems with the WCAG 2 contrast math have been known for some time and widely criticized. Including studies by others showing that color insensitive types are not well served.
The WCAG 2 contrast specs often cause enough problems for designers that it is ignored and today, some 86% of websites are failing WCAG 2 contrast per an automated survey—though some of these failures are not due to poor actual accessibility, but due to the perceptual inaccuracies of WCAG 2 contrast.
The unfortunate end result is a grave distrust of the WCAG 2.x accessibility standards overall, despite the many other important aspects of those standards.
Prima Facia Evidence and Public Comment
Outside of the peer reviews, third party reviews, and the extended 2.75 years of public test data collected thus far, you as a user can make your own judgements, using these tools and inspecting the results.
For instance, look at the following examples of minimum compliance for content for WCAG 2 (left) and APCA (right). Which one would you rather defend in a court of law? Which one would you rather have sites follow?
Public Comment and Discussion
Public comment and discussion is encouraged. The APCA discussion forum is alive and well, please join in the discussion, share and discuss your findings as part of the open public evaluation.
More About APCA, Direct from the Creators
The easy quickstart to becoming an expert in perceptually uniform contrast guidelines.
Smashing Magazine
Discussions on Contrast, Design, WCAG & APCA
The following articles, blogs, gists, and documentation written by APCA research lead Andrew Somers, examine the technical and functional differences between APCA and WCAG 2. Some of these are work-in-progress pre-prints relating to ongoing research.
Better Reading on the Web Published by UX Collective, this article discusses and demonstrates issues with automated testing and WCAG 2 contrast math, methods, and guidelines.
The Tangled Web tech blog (TangledWeb.xyz):
Thank you for reading.