Succession Criteria 2.3.1

[Chris Reeve]

Please strike G15 to allow "Ensuring that content does not violate the general flash threshold or red threshold". Please modify this so criteria G15 requires "Ensuring that content does not violate the general flash and red flash threshold".

 

Under G15, Someone could fail one technique, but pass another technique, and it their site would still pass. However, it would still increase the risk of seizures.

 

Also, please revise the 3-50 Hz so it is not resticted to 25% of a 1025x768 monitor. Please set the web based requirement at the full site.

 

Also please "consider" that it 2.3.1 must be used in conjuction with Pause Stop Hide, Technique 2.2.2.

[David Dorward-3]

On 28 Oct 2009, at 14:27, Chris Reeve wrote:

I think you mean "Success Criteria". "Succession" means something  
completely different.

> Please strike G15 to allow "Ensuring that content does not violate  
> the general flash threshold or red threshold". Please modify this so  
> criteria G15 requires "Ensuring that content does not violate the  
> general flash and red flash threshold".

The existing language is correct. To express it in programatic terms:

if ( violates_flash() || violates_red() ) { fail() }

You propose:

if ( violates_flash() && violates_red() ) { fail() }

which would only fail if both the General Flash threshold and the Red  
Flash were exceeded.

If the title of the guideline is unclear, then the full text of it  
certainly is not:

                        use a tool that to determine that neither the General Flash nor Red  
Flash
                        threshold were exceeded

> Under G15, Someone could fail one technique, but pass another  
> technique, and it their site would still pass.

Of course.

                        The "sufficient techniques" are considered sufficient by the WCAG  
Working
                        Group to meet the success criteria. However, it is not necessary to  
use these
                        particular techniques.
                                — http://www.w3.org/TR/2008/NOTE-WCAG20-TECHS-20081211/intro.html

> Also, please revise the 3-50 Hz so it is not resticted to 25% of a  
> 1025x768 monitor. Please set the web based requirement at the full  
> site.

Why?

>  Also please "consider" that it 2.3.1 must be used in conjuction  
> with Pause Stop Hide, Technique 2.2.2.

So if looking at a page triggers a seizure, then the user can turn off  
the flashing? I think it would be a *little* bit late by then.

--
David Dorward
http://dorward.me.uk

[Shawn Henry]

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~Shawn


-----
Shawn Lawton Henry
W3C Web Accessibility Initiative (WAI)
e-mail: shawn@...
phone: [phone]
about: http://www.w3.org/People/Shawn/




Chris Reeve wrote:

> Please strike G15 to allow "Ensuring that content does not violate the
> general flash threshold or red threshold". Please modify this
> so criteria G15 requires "*Ensuring that content does not violate the
> general flash and red flash threshold*".
>  
> Under G15, Someone could fail one technique, but pass another technique,
> and it their site would still pass. However, it would still increase the
> risk of seizures.
>  
> Also, please revise the 3-50 Hz so it is not resticted to 25% of a
> 1025x768 monitor. Please set the web based requirement at the full site.
>  
> Also please "consider" that it 2.3.1 must be used in conjuction with
> Pause Stop Hide, Technique 2.2.2.
>
>