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Requirements doc

From: Alastair Campbell <acampbell@nomensa.com>
Date: Thu, 18 Feb 2016 17:03:29 +0000
To: public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>
Message-ID: <BFFAF72B-69CB-4C93-BF8C-BB3A244A959B@nomensa.com>
Hi everyone,

This is my first post here, I’ve recently (re)joined the WCAG group and the LVTF is an area of interest for me. 

I’ve been through the requirements document in some detail, I hope this is a suitable place to post comments? I’m happy to split them up per-section somewhere else if that helps?


I had been looking for a summary of the less common low-vision issues and requirements for a while, and this is a good one. I really like that it is describing the issues users have, and the requirements derived from that, but doesn’t talk about solutions yet. 

Having said that, my mind immediately tries to work out how I can make a website that helps, so please forgive me for looking forward! 

There are some detailed comments below, but my main concern is about 3.7.1 (Seeing All Interface Elements) in combination with some of the others.

The requirement is: "Users can see all interface elements that are intended for users to see, including when users have changed display settings such as text size."

I’m worried that the ability for developers to create a  website that works for mobile (and zoom), and works when text is *also* expanded is unproven, and I think unmanageable for a site of reasonable complexity.

We did liquid layouts from 2001 [1], with all the tricks that you needed to pull in order to allow for text-sizing, it is  very familiar territory. With browser-zoom becoming ubiquitous and then media queries being supported we switched to responsive web design (RWD) which has been far more effective in almost every way.

Jared from Webaim said that for their clients: "supporting WCAG’s 200% requirement via text sizing to be extremely burdensome and difficult (often more so than captioning).” [2]  Our experience is similar. 

I’d really like to bottom-out where zoom on RWD sites is not enough from a sizing point of view, and see if it is possible to address the requirements within that context, without adding another variable of text-sizing.

I fully support adding extended success criteria (as noted in [2]), but only in a way that is achievable. 


For the colour scheme changes, are there good references for the useful colour combinations? If not, I know the BBC conducted or used some research on that a while ago, I can contact someone who might be able to track that down.


3.2.2 Reflow to Single Column: It would be useful to answer whether that reflow needs to be independent of sizing, i.e. would zooming on a desktop browser be sufficient, or do you need to reflow without increasing the size of text?

3.3.1 Text-Size: "Users can change the text size (font size) of all text, without zooming the entire interface.” 
That seems to be a jump, what is the requirement that means zoom isn’t enough? I.e. why is it a problem if everything gets smaller (or bigger).

3.3.2 Font: It mentions sub-pixel rendering (SPR) in the description which got me investigating that, but then I got to the requirement which had nothing to do with SPR. Is it a bit of a red herring in the document? 

3.5.1 Element level customisation: It appears to require pretty much a custom style sheet, where all text-based styling from the website is dumped in favour of a user’s styles. You could possibly retain some types of layout, but it is easy to see how clashes could make it unusable without something like profiles [3].

3.6 “Point of regard” seems to be a odd phrase, it is probably too late but “Visual focus” or "area of visual focus” would make more sense to me. 

3.6.1 user need: "The point of regard remains visible within the viewport when the viewport is resized, when content is zoomed or scaled, or when content formatting is changed."
That isn’t possible past a certain point. If you zoom in from 100% to 200%, something has to go. 

It is especially hard to understand how to deal with because ‘point of regard’ is not a point, it is an area of unspecified size.
I think some issues within this area (like pop-overs that don’t fit in the viewport) have solutions, but as a general requirement it isn’t tenable.

That’s everything I could think of, sorry it’s a bit late for the First Public Working Draft. I can’t make the Wednesday calls (very often), but I’m happy to discuss & contribute asynchronously.

Kind regards,


1] http://zomigi.com/blog/the-liquid-web-site-motherload/

2] https://alastairc.ac/2013/08/browser-zoom-great-for-accessibility/#comment-165794

3] https://alastairc.ac/2007/05/user-agent-improvements/#profiles

Received on Thursday, 18 February 2016 17:04:04 UTC

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