RE: Target size

From my personal experience small targets can be problematic for some pointer users with low vision.  Some folks such as myself with low vision may not want to use much magnification because of field loss, scotomas and clicking small areas can be very difficult with eye hand coordination.  As Alastair points out - many of these situations may end up passing due to target offset or an exception - but a few will get caught and fail - a tree with checkboxes where the expand/collapse and checkbox are close to each other.

Another issue that impacts some of us with low vision is target density where you press the wrong touch target because of holding a mobile device closely with monocular vision.  In these cases, 24x24 is likely to not be enough as you point out.  For example, an on-screen keyboard - e.g. the one on Wordle which is provided by the site. However, there are situations like a clear button within an input field where the SC could help.

So, while the benefit is minimal in some situations it would help in situations such as when targets are included inside other targets and when multiple small things are next to each other and it will help to get the need for target size on the minds of more designers.

Jonathan

From: Alastair Campbell <acampbell@nomensa.com>
Sent: Wednesday, December 7, 2022 5:49 AM
To: WCAG list (w3c-wai-gl@w3.org) <w3c-wai-gl@w3.org>
Subject: Target size

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Hi folks,

I may be having a moment of (self) doubt on target size, trying to work through the various issues and possibilities on the spacing and inline exceptions.

As mentioned in the survey, some people in the group (including people from the mobile TF) are concerned about the effectiveness of the SC. I want to check if the effort to resolve the remaining issues is worthwhile, or I'm falling into the sunk-cost fallacy<https://www.behavioraleconomics.com/resources/mini-encyclopedia-of-be/sunk-cost-fallacy/>.

On the positive side:

  *   Everyone knows small targets are problematic, and much more so for people with mobility impairments.
  *   We have done considerable honing of the SC.

On the negative side:

  *   When you look around at most sites, particularly those which have put effort into the display on mobile devices, they tend to easily pass the SC.
  *   Most things which are under 24px seem to fall into one of the exceptions anyway, either with spacing or being in text.
  *   The most common fails I can find are on adverts (e.g. close buttons), and those ads also fail several other SCs already for other reasons. (I.e. they are unlikely to meet this SC either.)
  *   Depending on the definition of "inline" we use, it will either provide quite a sweeping exception, or a relatively narrow one and capture a lot of (arguable) ok targets. It will also have a lot of potential for arguments.
  *   Whichever definition of spacing we use will have some odd effects, either how to test it, or what passes.
  *   Other SCs like text-spacing and reflow provide methods for increasing the size of targets in some circumstances.

A lot of the problems this SC faces are inherent in the web, where the same site is provided to small touch screens and larger screens with a mouse/trackpad. Someone with low-vision and zoomed-in may not want larger targets in the toolbar for an editor. But it's the same interface as someone with good vision and tremors.

If we could have a guideline that said "targets should be >44px unless there's a good reason not to", it would be fine. But in a binary pass/fail scenario that could become a legal requirement...

Am I off base? Can anyone talk me down?

Kind regards,

-Alastair

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@alastc / www.nomensa.com<http://www.nomensa.com>