RE: 1100% enlargement

I posted my (long winded) comments on the github thread. Reposted here for discussion:
You are never going to get agreement on what the minimum text size should be because everyone is going to have different needs. The most important part of this SC is that text can be resized without requiring horizontal scrolling.

As a low vision person myself and having trained many people with low vision I've observed that the level of magnification needed varies a lot depending on the person and even the situation. I myself can vary between 2x and 6x depending on the situation.

Requiring such a high level of magnification without the use of AT is problematic for a number of reasons:
- User agents and Operating Systems are limited in their support in text size changes with most settings limited to 200% without making use of hidden or unsupported configuration settings.
- Adjusting the text size without also adjusting other aspects of the UI will create layout and presentation issues that the UI may not be able to adjust for and this problem only gets worse as the text size increases. Windows, while it has gotten better, is particularly bad about this. Anyone who has tried to use the large or extra large themes included with Windows will notice very quickly that many if not most application exhibit display issues when the text is larger than normal. Most web browsers will only enlarge text up to 200%-300% using the standard UI and most browsers now default to zooming the entire UI not just the text which will likely cause horizontal scrolling. The web in theory can handle this much better but in practice most sites these days have layouts that restrict their layouts. Responsive design is helping reverse this somewhat but in most cases it is not responsive enough to cover all possible situations.

One aspect of the current SC that has me concerned is the full screen requirement. My vision for example is somewhat restricted so when reviewing the screen even without magnification I can not see the entire screen at once and if I enlarged the text to the point I could read from a distance so I could see the entire screen I would not be able to see the non-text portions of the UI very well if at all. Just the other day I was playing a video game where the game put button sequences on the edges of the screen. Being only able to see about 1/4 of the screen at a time I spent a good 20 minutes trying to figure out why I could not get further in the game because the game was showing a button sequence on the left edge of the screen (outside my field of vision) so until I backed up enough to observe the entire screen and could see the icons pop up on the various edges I didn't know what to do. Some users (like me) would prefer to have a browser window set to a manageable size and still be able to read without horizontal scrolling.

We need to be less restrictive in our requirements here. At the end of the day we are trying to say the text should be readable when the font size is increased as this is what typically happens when text is magnified without the use of AT. This ultimately means the text and associated layout needs to linearize properly without the need for horizontal scrolling.

I'd suggest something like this:
5.Text can be resized without assistive technology @@at least@@ 200 percent in a way that does not require the user to scroll horizontally to read a line of text

This is a small change but it says that 200% is now the minimum rather than the target maximum. It also takes away the full screen expectation as this could be a way for authors to make width assumptions that could cause horizontal scrolling or other UI problems. If the UI can linearize properly we should have very few cases where horizontal scrolling is the only option.

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Scott McCormack
Principal Technical Consultant  -- IT Manager
SSB BART Group
scott.mccormack@ssbbartgroup.com
(415)624-2712 (o)
www.ssbbartgroup.com

From: Wayne Dick [mailto:wayneedick@gmail.com]
Sent: Sunday, July 10, 2016 9:34 AM
To: public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>
Subject: 1100% enlargement

The size 1100% seems crazy o first glance, but it is very practical for reading. I first thought of getting all logical, but an example is better. Look at WCAG 1.4.8 Issue #5.  I have included a screen shot of 1100% enlargement of 16px on a 22 inch screen. It looks like a reasonable reading interface to me.
Take a look. https://github.com/w3c/low-vision-SC/issues/5

Wayne