RE: Best place for revised Pointer Target Spacing

Hi Alastair –

Here is what the mobile taskforce is proposing for the wording on the SC.

For each target that has a width or height less than 44 CSS pixels, the target area has a width and height of at least 24 CSS pixels with a minimum spacing on the height and width of 4 CSS pixels where the spacing cannot overlap.

The 24 CSS px comes from Microsoft’s research where they are recommending a target area of 24px with a minimum of 16% spacing.  If we look at the minimum that is 3.8px so we rounded that to 4 CSS pixels.

Kathy
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From: Alastair Campbell <acampbell@nomensa.com>
Sent: Thursday, September 10, 2020 10:47 AM
To: Sarah Horton <sarah.horton@gmail.com>
Cc: jake abma <jake.abma@gmail.com>; Detlev Fischer <detlev.fischer@testkreis.de>; Mobile Accessibility Task Force <public-mobile-a11y-tf@w3.org>
Subject: RE: Best place for revised Pointer Target Spacing

Hi Sarah,

I think the Apple & MS resource are for providing app icons, the assets, they don’t speak to target sizes. For example, the smallest icons would probably best used in contexts like favicons, little icons within a larger component that might not even be interactive.

I think the Mobile task force are meeting in about 15 minutes:
https://www.w3.org/2002/09/wbs/66524/telco/


Hopefully they will have a chance to discuss it. Sorry for providing that very last minute, I just got out of a run of meetings ☹

Cheers,

-Alastair


From: Sarah Horton <sarah.horton@gmail.com<mailto:sarah.horton@gmail.com>>
Sent: 10 September 2020 12:20
To: Alastair Campbell <acampbell@nomensa.com<mailto:acampbell@nomensa.com>>
Cc: jake abma <jake.abma@gmail.com<mailto:jake.abma@gmail.com>>; Detlev Fischer <detlev.fischer@testkreis.de<mailto:detlev.fischer@testkreis.de>>; Mobile Accessibility Task Force <public-mobile-a11y-tf@w3.org<mailto:public-mobile-a11y-tf@w3.org>>
Subject: Re: Best place for revised Pointer Target Spacing

Thanks, Alastair!

I was wondering if we could look at interface guidelines for desktop apps for a minimum size for icons, for example, Apple’s minimum size is 16 x 16:

https://developer.apple.com/design/human-interface-guidelines/macos/icons-and-images/app-icon/

https://developer.apple.com/design/human-interface-guidelines/macos/icons-and-images/custom-icons/


And Windows is also 16 x 16:

https://docs.microsoft.com/en-us/windows/uwp/design/style/app-icons-and-logos#more-about-app-icon-assets


That’s assuming those are research-informed minimums (you’d hope!!).

For menus, I didn’t see any specification the item height in the interface guidelines as I think those are not defined by the author—the contents are but not the presentation.

Hope this helps!

I’m away next week and won’t be available to meet.

Best,
Sarah


On Sep 9, 2020, at 6:39 PM, Alastair Campbell <acampbell@nomensa.com<mailto:acampbell@nomensa.com>> wrote:

Hi folks,

Sorry, I need to update my filters as these didn’t get to my inbox (Detlev’s should have).
Also, adding Sarah to the CC list as she expressed interest.

Yesterday we discussed [1] the target-pointer-spacing criteria, with reference to issues #1312 and #1361, and since then also issue #1384 [2].

My overview is that dealing with the various issues<https://github.com/w3c/wcag/labels/2.5.8%20Pointer%20Target%20Spacing> means we need to either:

  *   Have a minimum size that is smaller (e.g. 26px) at AA, and forget about the spacing aspect.
  *   Keep the current size/spacing metrics but not allow targets to share spacing (so smaller targets are not incentivised).
  *   Something else.
  *   Drop the SC.

The core problems (IMHO) were that:

  *   With shared spacing, it can incentivise making targets smaller if they are in a row/list. That may not be an issue for hitting them per-se, but would impact people with low vision.
  *   Lots of tool-bars and vertical lists of links would not pass, it seems like something that would be better dealt with by personalisation rather than reducing the information density for everyone. Thus the suggestion that we used a smaller target size to catch the really tiny targets.

If there isn’t space on the MAFT agenda this week (or next), we could setup a specific call?

Cheers,

-Alastair

1] https://www.w3.org/2020/09/08-ag-minutes.html#item12

2] https://github.com/w3c/wcag/issues/1312

https://github.com/w3c/wcag/issues/1361

https://github.com/w3c/wcag/issues/1384



From: jake abma <jake.abma@gmail.com<mailto:jake.abma@gmail.com>>
Sent: 09 September 2020 17:55
To: Detlev Fischer <detlev.fischer@testkreis.de<mailto:detlev.fischer@testkreis.de>>
Cc: Mobile Accessibility Task Force <public-mobile-a11y-tf@w3.org<mailto:public-mobile-a11y-tf@w3.org>>
Subject: Re: Best place for revised Pointer Target Spacing


As I think Kathy has done a lot of work here and has a clear view on this let's discuss this and ask her about the history and research.

Op wo 9 sep. 2020 om 15:22 schreef Detlev Fischer <detlev.fischer@testkreis.de<mailto:detlev.fischer@testkreis.de>>:

Am 09.09.2020 um 15:04 schrieb jake abma:
Just a small reminder that the intent was not to have another SC text with a smaller target size, but to have a least a 8 CSS px distance between adjacent targets (morphed into the current text)

Hi Jake,
I thought working with a smaller size was what had emerged as an alternative approach favoured by some in the last WG telco - but of course am open to other approaches. Setting a lower target size for an AA requirement may be easier to understand, and it would avoid the detrimental approach of reducing target size in order compress groups pf targets (as would probably also happen if we set 8px as minuimum distance).

The other potential negative impact of an 8px distance requirement would be the incentive to create targets with gaps rather than including padding (of icons or text links)  in the active target area, which at least for mouse users would be better than gaps (I guess the tap heuristics make this less of a problem under mobile OSs).

Best,
Detlev


Cheers!

Op wo 9 sep. 2020 om 14:53 schreef Detlev Fischer <detlev.fischer@testkreis.de<mailto:detlev.fischer@testkreis.de>>:
Hi ALastair,

I wondered whether it would help to create an issue for the reset of
Pointer Target Spacing - or what would you suggest is the best approach?
My personal hunch is that it might be easiest to start from the
normative text of our AAA SC Target size, just with a smaller target
value like 26 x 26px. That woud seem most consistent. This could easily
done - but I guess just doing that as a pull request on the SC text
would leapfrog the discussion we will likley want to have before that?
CC'ing Mobile a11y TF...

Best,
Detlev

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Detlev Fischer
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--

Detlev Fischer

DIAS GmbH

(Testkreis is now part of DIAS GmbH)



Mobil +49 (0)157 57 57 57 45



http://www.dias.de<http://www.dias.de/>

Beratung, Tests und Schulungen für barrierefreie Websites