Re: 48px vs 44px target sizing

Here is reference 15.
http://www.ncbi.nlm.nih.gov/pubmed/22768644


Cheers,
David MacDonald



*Can**Adapt* *Solutions Inc.*
Tel:  613.235.4902

LinkedIn
<http://www.linkedin.com/in/davidmacdonald100>

twitter.com/davidmacd

GitHub <https://github.com/DavidMacDonald>

www.Can-Adapt.com <http://www.can-adapt.com/>



*  Adapting the web to all users*
*            Including those with disabilities*

If you are not the intended recipient, please review our privacy policy
<http://www.davidmacd.com/disclaimer.html>

On Mon, Sep 5, 2016 at 11:02 AM, David MacDonald <david100@sympatico.ca>
wrote:

> I've tracked down the Reference 16 in the document.
> http://link.springer.com/article/10.1007/s10209-013-0320-5
>
> Reference 17 is here:
> http://link.springer.com/chapter/10.1007%2F978-3-540-73279-2_104
>
> It should be noted that for the study I summarized previously, the users
> had the device on a table that they were sitting at, and so they were in
> close proximity and they were using a tablet Samsung.
>
>
>
>
> this might be helpful.
>
> Cheers,
> David MacDonald
>
>
>
> *Can**Adapt* *Solutions Inc.*
> Tel:  613.235.4902
>
> LinkedIn
> <http://www.linkedin.com/in/davidmacdonald100>
>
> twitter.com/davidmacd
>
> GitHub <https://github.com/DavidMacDonald>
>
> www.Can-Adapt.com <http://www.can-adapt.com/>
>
>
>
> *  Adapting the web to all users*
> *            Including those with disabilities*
>
> If you are not the intended recipient, please review our privacy policy
> <http://www.davidmacd.com/disclaimer.html>
>
> On Mon, Sep 5, 2016 at 10:36 AM, David MacDonald <david100@sympatico.ca>
> wrote:
>
>> I agree we have to look carefully... we want to have a WCAG 2.1 that
>> makes sense to all, otherwise WCAG 2.1 will end up like the sequels to the
>> "Matrix"... flat and not accepted by our stakeholders.
>>
>> I've read through the reference sent by John looking for things that
>> might help us... there are also several useful references that we may want
>> to look up. There are 4 pages missing from the 16 page report in the Google
>> book version but I think I can pull the major parts of it. Here are some
>> quotes and a summary of key findings pertinent to our work.
>>
>> "When creating the prototype, we referred to research on appropriate
>> button size [ 14, 15], button spacing [ 15, 16], and touchscreen gestures
>> and button position [11, 17]. In our mobile voting user interface design,
>> buttons arc located near the edges of the screen and the active region of
>> each button is at least 20 mm in length and width (although the visual size
>> may appear smaller), with at least 6.35 mm of spacing between active
>> regions. Where buttons arc touching, the minimum button size was increased
>> to provide additional spacing. All functionality is accessed via tap, which
>> is the preferred and most effective gesture for individuals with motor
>> skill impairments [ 11 ]"
>>
>> "although the amount of spacing included between these buttons and the
>> placement of the buttons along the edges of the screen was based on
>> previous research, we observed that his spacing proved insufficient,
>> especially for w participants who tended to experience drifting. This
>> proximity of repeated-press buttons led to accidental presses of the Next
>> Contest button ... "
>>
>>
>> ​Here's a summary of other points.
>>
>>    - Buttons in study were were 20mm = 75px with spacing of   6.35mm =
>>    24 px  (conversion here https://css-tricks.com/the-lengths-of-css/ )
>>    This was based on research listed below.
>>    - Users did better with mobile device on slanted table​
>>    - Resting hand alongside of the device for support helps some users
>>    - buttons on edge were better because user could support arm
>>    - left and right hand versions of software are helpful for this reason
>>    - 4 out of 16 participants did not have success when they touched the
>>    Samsung Galaxy Tab4, probably because of excessive dwell times were
>>    recognized as double press rather than single.
>>    - some users used their thumbs and fingers other than the index finger
>>    - Button placement personalization would be helpful.
>>    - People with dexterity problems required twice the time. (literally)
>>    - Accuracy of control group wass 88.8% vs 65.3% for users with
>>    dexterity problems. 4 users w/ disabilities failed the task with less than
>>    70%.
>>    - much of their findings is consistent with previous literature.
>>
>>
>> References #11, 14, 15, 16​, 17 are as follows:
>>
>> 11, and 14 are on pages left out of the Google book.
>>
>> 15. Touch screen user interfaces for older adults: button size and
>> spacing (Jin, Z.X, Plocher, T. Kiff, L., HCI 2007 LNCS Vol 4554. pp.
>> 933-941, Springer, Heidelberg 2007
>> 16.  Effect of touch screen button size and spacing on touch
>> characteristics of users with and without disabilities. Human Factors
>> Ergonomics Soc. 54(3), 425-436 (2012), Sesto, M.E. Irwin, C.B., CHen, K.B,
>> Chourasia, A. O, Weigmann. DA
>>
>> 17.  Mobile touchscreen user interfaces: Bridging the gap between
>> motor-impaired and able bodied users. Univ. Access Inf. Soc. 13, 303-313
>> (2014)
>>
>>
>> Here's the research paper John referred to summarized here.
>>
>> https://books.google.com/books?id=9hOfDAAAQBAJ&pg=PA159&lpg=
>> PA159&dq=Touchscreen+voting+interface+design+for+persons+wit
>> h+disabilities:+Insights+from+usability+evaluation+of+mobile
>> +voting+prototype&source=bl&ots=2a0DJQeVh6&sig=vnbIDBLP6OQ
>> cTO-EJIp9L30eM2c&hl=en&sa=X&ved=0ahUKEwjruJqjudvOAhVDtRQKH
>> b-bCGoQ6AEIMjAE#v=onepage&q=Touchscreen%20voting%20interface
>> %20design%20for%20persons%20with%20disabilities%3A%20Insight
>> s%20from%20usability%20evaluation%20of%20mobile%20voting%
>> 20prototype&f=false
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Cheers,
>> David MacDonald
>>
>>
>>
>> *Can**Adapt* *Solutions Inc.*
>> Tel:  613.235.4902
>>
>> LinkedIn
>> <http://www.linkedin.com/in/davidmacdonald100>
>>
>> twitter.com/davidmacd
>>
>> GitHub <https://github.com/DavidMacDonald>
>>
>> www.Can-Adapt.com <http://www.can-adapt.com/>
>>
>>
>>
>> *  Adapting the web to all users*
>> *            Including those with disabilities*
>>
>> If you are not the intended recipient, please review our privacy policy
>> <http://www.davidmacd.com/disclaimer.html>
>>
>> On Mon, Sep 5, 2016 at 9:00 AM, Alastair Campbell <acampbell@nomensa.com>
>> wrote:
>>
>>> David wrote:
>>> > “We've seen studies recommending up to 57px... We went back and forth
>>> on 50 px but dropped it to 48px for the very reason you mention regarding
>>> Android devs...  Are you recommending further reduction?
>>> > It would make sense for an accessibility standard to take the upper
>>> limit not the lower....”
>>>
>>> Ideally there would be a well-researched, known minimum size that easily
>>> translates into CSS pixels, and the platform standards would all use that.
>>>
>>> However, we aren’t there so I think it would help to have a common
>>> ‘story’, either:
>>>
>>> - It uses the lower end of the platform standards and we can say “use
>>> platform standards”.
>>>
>>> OR
>>>
>>> - It uses something larger than any of the platform standards, so we can
>>> say “The platform standards aren’t enough, please make targets bigger”.
>>>
>>> Choosing the upper end of the platform standards is messy, it means that
>>> some developers don’t have to worry, others do.
>>>
>>> So there are three options compared to the platform standards: 1) lower
>>> end; 2) upper end; 3) above.
>>>
>>> In the case of 2 or 3, there needs to be a good rational for why the
>>> platform standard (i.e. iOS) is not large enough.
>>>
>>> Sorry that I have probably missed that reasoning, but this is the type
>>> of push-back that Alan was talking about so I’m just trying to preempt it!
>>>
>>> Cheers,
>>>
>>> -Alastair
>>>
>>>
>>>
>>
>