Re: Mobile needs a question answered

Alastair,
As the question originally came from the Mobile group, I am looping them
into the conversation. Perhaps they can add comments.

Based on several articles - seems 8dp is a reasonable spacing.

*"Touch targets should also be spaced about 8 pixels apart, both
horizontally and vertically, so that a user's finger pressing on one tap
target does not inadvertently touch another tap target."*
https://developers.google.com/web/fundamentals/accessibility/accessible-styles

*"**To balance information density and usability, touch targets should be
at least 48 x 48 dp with at least 8dp of space between them." *-
https://material.io/design/layout/spacing-methods.html#touch-click-targets

https://medium.com/@zacdicko/size-matters-accessibility-and-touch-targets-56e942adc0cc

one caveat - the articles all point back to google/android specs. Most
other articles related to target spacing are vague ("reasonable space", "a
good amount of space", etc.) and are not helpful.

other Related stuff I found while searching for target spacing.
an old article with lots of research
https://www.uxmatters.com/mt/archives/2013/03/common-misconceptions-about-touch.php

Reading Digital with Low Vision - NCBI - NIH
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5726769/
<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5726769/>
http://www.4ourth.com/Touch/

On Wed, Jan 30, 2019 at 8:47 AM Wayne Dick <wayneedick@gmail.com> wrote:

> Hi Alastair,
> It kind of reduces to the same thing. It easy to miss a target you cannot
> separate from another. I'm a little embarrassed to admit how many times I
> hit the wrong target.
> Wayne
>
> On Wed, Jan 30, 2019 at 12:41 AM Alastair Campbell <acampbell@nomensa.com>
> wrote:
>
>> Hi Jim,
>>
>> Was that for seeing things, or hitting the targets?
>>
>> Those seem like different problems, especially as the touch-screen OSs
>> have heuristics so that if you tap between two targets, it guesses which
>> you meant...
>>
>> -Alastair
>>
>> Apologies for typos, sent from a mobile.
>>
>> ------------------------------
>> *From:* Jonathan Avila <jon.avila@levelaccess.com>
>> *Sent:* Tuesday, January 29, 2019 11:45 pm
>> *To:* Wayne Dick; Jim Allan
>> *Cc:* public-low-vision-a11y-tf
>> *Subject:* RE: Mobile needs a question answered
>>
>>
>> HI Wayne, I also think that people with low vision might need more space
>> because touch might not be as precise given that a person may be holding
>> the device closer to their face and not have the same perspective as
>> distance.  Also scotomas may also impact touch target accuracy for some
>> users.
>>
>>
>>
>> Jonathan
>>
>>
>>
>> Jonathan Avila, CPWA
>>
>> Chief Accessibility Officer
>>
>> *Level Access*
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>>
>> *From:* Wayne Dick <wayneedick@gmail.com>
>> *Sent:* Tuesday, January 29, 2019 5:24 PM
>> *To:* Jim Allan <jimallan@tsbvi.edu>
>> *Cc:* public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>
>> *Subject:* Re: Mobile needs a question answered
>>
>>
>>
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>>
>> Hi All,
>>
>> Well all zoomed pixels are large, but that is only so that we can see
>> them. So, I would assume that it takes 2-pixels for full sighted readers to
>> separate things, it would take us 2 big pixels to distinguish things.
>>
>>
>>
>> Wayne
>>
>>
>>
>> On Tue, Jan 29, 2019 at 1:47 PM Jim Allan <jimallan@tsbvi.edu> wrote:
>>
>> How many pixels in between 2 active elements on a screen meets user need
>> on the low-vision side? Mobile TF have it at two pixels.
>>
>> And does the overall target size impact the spacing between elements
>> requirement?
>>
>> Anybody have any ideas or research?
>>
>>
>>
>>
>>
>>
>>
>> --
>>
>> Jim Allan, Accessibility Coordinator
>>
>> Texas School for the Blind and Visually Impaired
>> 1100 W. 45th St., Austin, Texas 78756
>> voice 512.206.9315    fax: 512.206.9452 http://www.tsbvi.edu/
>>
>> "We shape our tools and thereafter our tools shape us." McLuhan, 1964
>>
>>

-- 
Jim Allan, Accessibility Coordinator
Texas School for the Blind and Visually Impaired
1100 W. 45th St., Austin, Texas 78756
voice 512.206.9315    fax: 512.206.9452 http://www.tsbvi.edu/
"We shape our tools and thereafter our tools shape us." McLuhan, 1964