Justification of text

[aphillips]

https://www.w3.org/TR/WCAG22/#visual-presentation

Section 1.4.8 says:

Text is not justified (aligned to both the left and the right margins).

I18N notes that: This does not apply to all writing systems. For example, Chinese and Japanese prefer fully justified text to left-aligned text. See the last paragraph of clreq 3.5.1 Necessity for Line Adjustment and jlreq 3.8.1 Necessity for Line Adjustment.

There is a comment from @alastc in #2680 here pointing out that the SCs here allow individual users to override author's spacing (and, in this case, justification), not specific guidance forcing any specific justification onto a document.

The "understanding" doc here says:

People with certain cognitive disabilities have problems reading text that is both left and right justified. The uneven spacing between words in fully justified text can cause "rivers of white" space to run down the page making reading difficult and in some cases impossible. Text justification can also cause words to be spaced closely together, so that it is difficult for them to locate word boundaries.

Note that CJK languages in particular use other strategies to manage text so that it aligns into columns, so the above description rarely applies to these languages. Other languages have different strategies for managing whitespace during justification (such as kashida in Arabic script).

It is unclear in the the understanding guide when to apply this SC to non-Latin-script writing systems.

This issue doesn't have a specific textual ask (unless it would be to clarify the understanding section or perhaps the author responsibility section).

[alastc]

Overall, it seems that the core requirement (allow users to over-ride the justification of text) may not be a problem for other writing systems, but it may not be necessary?

What I don't know is the user-requirement aspect for other writing systems. The links above go to docs based on the rules of the writing system, but I have questions like:

• Is dyslexia a thing for people using other writing systems? (e.g. in Japan)
• If so, does adjusting the justification help? (I'd naively assume so as it's based on eye tracking).
• How does someone with low-vision read when they increase the size of those writing systems?

[murata2makoto]

Is dyslexia a thing for people using other writing systems? (e.g. in Japan)

Yes, some of my colleagues in the Japanese DAISY Consortium are dyslexic.

If so, does adjusting the justification help? (I'd naively assume so as it's based on eye tracking).

Justification in the Japanese language does not make word spacing too much since JP text typically does not use word spacing. Justification may increase character spacing. However, as far as I know, nobody thinks such character spacing is bad for accessibility.

For some dyslexic Japanese, word spacing (called Wakachi-gaki) is useful. In this case, too wide word spaces might be problematic. One DAISY reader in Japan uses justification when wakachi-gaki is enabled and does not use justification otherwise.

How does someone with low-vision read when they increase the size of those writing systems?

I do not know any particular requirements about justification, character spacing, and word spacing from low-vision people.

[aphillips]

I recommend that you close this issue as superseded by #3337 (which will be addressed by #3351)

[alastc]

Superseded by #3337