Clarified and included CJK requirements in large text definition and updated rules affected by this change

giacomo-petri commented 1 year ago

Since the WCAG is not unambiguously defining what "equivalent size for Chinese, Japanese and Korean (CJK) fonts" means, I've added the definition of large text for CJK languages, based on the Japanese translation of WCAG 2.1 with the assumption that it applies also to the other CJK languages.

Edits:

updated the large text definition;
updated ACT contrast minimum examples to reflect updates;
updated ACT contrast enhanced examples to reflect updates.

Closes #2068

Need for Call for Review: This will require a 2 weeks Call for Review

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giacomo-petri commented 8 months ago

Call for review ends on January 25th.

bobbytung commented 8 months ago

Hello,

I'm Bobby Tung, editor of CLREQ.

Some opinion here:

Japanese 22pt equivalent issue.

The Japanese font-size 22pt rules is from 第2章　拡大教科書の標準的な規格について, that is a formatting rule document for textbook designed for low vision student.

Usual Japanese textbook's base body text size is from 10.5pt, up to 18pt. In this document, its base body text size is from 22pt. However, it also asked for 0.8x (base body text is 18pt) and 1.2x (base body text is 30pt) layout as option for student to choose.

Since 0.8x version textbook's base body text size is 18pt, Should we keep the baseline on 18pt?

We do not apply Web a11y rule to print book, but if we do so, 0.8x version should be recheck for SC 1.4.3 and 1.4.6.

Traditional Chinese textbook rule as reference.

In Taiwan, we have a rule for textbool's base text size: 14pt is minimal size for body text and other text must not be smaller than 11pt. Practically, large size textbook for low vision student usually directly scale up to 1.25% to 1.5%. That means 18pt~22pt. So I'd like to keep baseline on 18pt.

Character complexity for CJK.

Additional information for consideration.

If we need to set minimal font size rule for CJK, I think glyph complexity and what type used inline (i.e. Katakana and Hiragana in Japanese) is important. The base font size:

Traditional Chinese ≥ Japanese ≥ Simplified Chinese

giacomo-petri commented 8 months ago

@Jym77 @carlosapaduarte,

What are your thoughts on adding this into the agenda items, if @bobbytung and @JediLin are able to join?

Jym77 commented 8 months ago

@Jym77 @carlosapaduarte,

What are your thoughts on adding this into the agenda items, if @bobbytung and @JediLin are able to join?

Yes, definitely.

Jym77 commented 8 months ago

Taiwan (Traditional Chinese, lang = zh-hant-tw or zh-tw) has different requirements than Japan (Japanese, ja). In the case of Traditional Chinese characters, for people with disabilities, 20 point or 16 point bold type is considered to be the "equivalent" size, based on the 臺灣易讀參考指南 (Taiwanese Readability Reference Guidelines), published by Social and Family Affairs Administration, Ministry of Health and Welfare, Taiwan.

Since the same characters may be used in different language, it is not sufficient simply using Unicode characters range to make exception rules. The value of lang attribution should be considered, too.

That's getting a bit tricky.

We can of course link the requirement to the lang of the text node (in addition to the unicode range). This would also require an assumption that the lang attribute is correctly set (how valid is this assumption?)
We can also go for a "maximum requirement" rule, with a background note stating that "different languages have different requirement even if they use the same script, thus less than X points is always 'small size', more than Y points is always 'big size', and between X and Y is unclear". Then, the rule consider "more than X points" as being 'big size' under the "no false positives" reasoning: anything less than X points with 3:1 contrast is sure to be bad, stuff more than X points with 3:1 contrast may be good.

JediLin commented 8 months ago

We can also go for a "maximum requirement" rule, with a background note stating that "different languages have different requirement even if they use the same script, thus less than X points is always 'small size', more than Y points is always 'big size', and between X and Y is unclear". Then, the rule consider "more than X points" as being 'big size' under the "no false positives" reasoning: anything less than X points with 3:1 contrast is sure to be bad, stuff more than X points with 3:1 contrast may be good.

I like the "maximum requirement" rule option with "no false positives" reasoning :-)

carlosapaduarte commented 8 months ago

@Jym77 @carlosapaduarte, What are your thoughts on adding this into the agenda items, if @bobbytung and @JediLin are able to join?

Yes, definitely.

@bobbytung and @JediLin, would you be able to join one of our meetings? They take place from 10:00 EDT to 11:00 EDT every second and fourth Thursdays. The next one is on January 25.

bobbytung commented 8 months ago

I'm not sure but try my best to attend.

However, I'd like to raise another issue.

As screenshot below, some system serif fonts for TC only have one font weight. (i.e. PMingLiu for MS Windows, Noto Han Serif for Android) That means browser may render as faux bold, it affects legibility a lot.

JediLin commented 8 months ago

They take place from 10:00 EDT to 11:00 EDT every second and fourth Thursdays. The next one is on January 25.

I'll do my best to keep awake. (Local time 23:00 to 00:00)

Jym77 commented 8 months ago

@giacomo-petri CG decision was to got with this solution:

We can also go for a "maximum requirement" rule, with a background note stating that "different languages have different requirement even if they use the same script, thus less than X points is always 'small size', more than Y points is always 'big size', and between X and Y is unclear". Then, the rule consider "more than X points" as being 'big size' under the "no false positives" reasoning: anything less than X points with 3:1 contrast is sure to be bad, stuff more than X points with 3:1 contrast may be good.

the rule is pretty much already doing the same sort of approximation by only grabbing the highest possible contrast.

giacomo-petri commented 8 months ago

Thanks @Jym77,

following the meeting's outcomes and the agreed-upon solution, we have designated the 18pt-22pt range as large text for CJK (and anything exceeding 22pt is considered large text as well). This aligns with the observed pattern in Latin languages.

While we acknowledge some disparities in CJK requirements, we have universally recognized text => 18pt (and 14pt bold) as large text, below as standard text, without any exceptions.

In the next couple of days, I will revert the large text definition to the original one and include background notes for contrast minimum and enhanced rules.

giacomo-petri commented 8 months ago

Files updated:

Added a note within the "Large text" definition for CJK languages and how we decided to treat them.
Eliminated passing CJK examples within the CJK range, since it was no longer pertinent based on the updated definition of large text.
Similarly, removed irrelevant failing examples as there's no longer a distinction between CJK and Latin characters.

giacomo-petri commented 6 months ago

Call for review ends on ~April 16th~ April 23rd (2 weeks).

Jym77 commented 5 months ago

Call for review has ended, merging.

act-rules / act-rules.github.io