As a user with some vision challenges, but not so many that I can't use sites like this at all or have to resort to screen readers, I'm feeling challenged by some aspects of the chat UI. I understand that it's a work in progress, and I'm here to ask for a few things that I think are small implementation efforts but would have large accessibility impact.
First some context. Because zoom affects the whole page, I have to find a balance among Q&A text, chat-message text, and UI elements. If I zoom the page enough to read the smallest things, the biggest things becaome *huge* and that impedes readability too. Larger isn't always better; the eye has a field of vision, a "chunk" that can be taken in at once, that is measured in physical dimensions, but the brain has a cognitive "chunk" size too. That's why you don't really want to read text one word at a time, for instance; you can *see* it just fine, but it's too irritating to *process*. On the computer I'm typing this on, I've balanced all of this to land at a zoom level of 110%, which isn't all that much. The text I'm typing in this edit window and the preview next to it are nice sizes for me. (For completeness, I'm also using the sans-serif font.)
Now, enter chat. Chat *messages* are a legible size and while lines are short (becuase of the width of the pane), they're not *too* short (for chat; long-form writing would be different). The *rest* of the chat UI, however, is tiny and hard for me to use:
- The icons next to messages are cryptic little gray things. Fortunately they mostly have tooltips now (thanks for adding those!), though there's one (I think "..."?) that doesn't. **Tooltips make the illegible accessible**; they're really important. They're not a silver bullet -- they don't help on touch interfaces -- but they're a simple thing that often helps, so please always use tooltips for graphical elements. (This is a general principle, not restricted to chat.)
- Messages are preceeded by *very* tiny text that includes the author, timestamp, and who it's replying to (if applicable). I can't read that. I've developed the heuristic that if the line of text seems long it's probably a reply and hovering over the message shows me the nice highlighting for replies, but otherwise that text isn't helping me. *That color-coding for reply hover is great* -- just wanted to say that.
- Messages are also preceeded by the author's gravatar. You might think that mitigates against the tiny text, but those gravatars are very small too. Please don't rely on them. Even on SE chat where they're bigger than here, I often can't tell people apart if their gravatars are similar -- and by "similar" I mean things that are more aobut color and shape and less about details. Many headshots look the same to me, and there are a few dogs on SE that I can't tell apart without extra effort. **To mitigate this**, it'd be great if the tooltip for those gravatars could be expanded to include the name -- "So and so, 32 stars" rather than "30 stars", and it's still short enough to not get in the way. I just noticed that you do that in the column of people in the room over on the right; if you could do it everywhere that'd be great. (Hey, go ahead and do it for the gravaters in the question list too, for consistency and that extra bit of help.)
- That stuff I said about tiny text applies to chat notifications, too. I've already accidentally dismissed messages when I was trying to jump to them. I hope we're going to improve notifications in other ways, so I won't say much about them here.
Finally, I'd like to point out some things that work well in chat -- thanks, and please keep them!
- Black text, white background -- nice and readable. There was a time this wouldn't have been remarkable, but alas... thank you for not falling for the "light gray text on white is good enough for everyone, right?" meme.
- That color highlighting for threads is great! First, that you have it at all and that it goes both directions, and second, that the color choice manages to draw attention without either impeding legibility or being harsh.
- The text size for messages plays well with the size for Q&A. It's smaller, befitting chat/comments, but it looks like it's only one notch down, so those of us who are more limited in what we can see can still see it all.