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Re: change proposal for <main>: possible validation warning heuristic for misuse

From: Steve Faulkner <faulkner.steve@gmail.com>
Date: Wed, 5 Dec 2012 07:22:01 +0000
Message-ID: <CA+ri+V=b5pG2OvDFKEPeVA_TX6HFKvOF5-c-_PxfCQewLuq_fg@mail.gmail.com>
To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Cc: Maciej Stachowiak <mjs@apple.com>, James Craig <jcraig@apple.com>, HTML Accessibility Task Force <public-html-a11y@w3.org>, Michael Smith <mike@w3.org>, Henri Sivonen <hsivonen@iki.fi>
Hi Silvia,

>Let's be careful what we write into the spec. We should not codify
something that is common usage right now, but won't work in the future.
Also, conversely, >we should not ignore something (Scooby Doo) that doesn't
work right now (because <header>, <nav> etc are not in common usage), but
might work very well >in a few years when most Web pages have picked up
<header>.

I agree we should be careful. From the stats below [1] which are from the
same data set that i used to check Scooby, we should be seeing a much
better success rate for Scooby than is evident.

Rough stats on new element usage on HTML5 pages 28% nav, 16% article, 31%
> header, 28% footer, 13% aside, 24% section. data set:http://www.
> paciellogroup.com/blog/2012/04/h
> tml5-accessibility-chops-data-for-the-masses/  <http://t.co/LGRwZBW9>


[1] https://twitter.com/stevefaulkner/status/270475603315146752

regards
SteveF

On 5 December 2012 06:56, Silvia Pfeiffer <silviapfeiffer1@gmail.com> wrote:

>
>
> On Wed, Dec 5, 2012 at 10:33 AM, Steve Faulkner <faulkner.steve@gmail.com>wrote:
>
>> On 1 December 2012 22:19, Maciej Stachowiak <mjs@apple.com> wrote:
>> > This would end up documenting the semi-mythical "Scooby Doo algorithm"
>> for
>> > cases when the <main> element is absent.
>>
>>
>> From what I understand, the Scooby Doo algorithm concept was derived from
>> section '4.13.1 The main part of the content' of the spec. It was named and
>> further elucidated by bruce lawson [2] . Mike Taylor produced a script
>> based on the concept [3]
>>
>> today I created a bookmarklet from the script (adds a dashed border and
>> yellow background to what it identifies as the main content)
>>
>> Scooby Doo
>>
>> and tested it out on a hundred or so of the pages using <!DOCTYPE html>
>> [4] I found that in approximately 95% of cases the algorithm identified the
>> main content as either including all of the page content or an element at
>> the very start of the page. In other words it is of little to no use in
>> determining either what the main content consists of or where it starts.
>
>
>> I think a much more useful algorithm would take into account id values
>> commonly used to identify the main content.
>>
>
> Let's be careful what we write into the spec. We should not codify
> something that is common usage right now, but won't work in the future.
> Also, conversely, we should not ignore something (Scooby Doo) that doesn't
> work right now (because <header>, <nav> etc are not in common usage), but
> might work very well in a few years when most Web pages have picked up
> <header>. This is why I did my analysis assuming Web pages would use those
> new elements - where would Scooby Doo end up?
>
> So, you could re-run your analysis by adapting your bookmarklet to run
> Scooby Doo not just on the defined elements, but also on elements that have
> a @class of header, nav, etc. That may be a bit fairer on Scooby Doo.
>
> Regards,
> Silvia.
>
>
>>
>> [1] http://dev.w3.org/html5/spec/links.html#the-main-part-of-the-content
>> [2] http://www.brucelawson.co.uk/2012/scooby-doo-content-element/
>> [3] http://pastie.org/4663081
>> [4] http://www.html5accessibility.com/tests/HTML5-main-content/
>>
>> regards
>> SteveF
>>
>
>


-- 
with regards

Steve Faulkner
Technical Director - TPG

www.paciellogroup.com | www.HTML5accessibility.com |
www.twitter.com/stevefaulkner
HTML5: Techniques for providing useful text alternatives -
dev.w3.org/html5/alt-techniques/
Web Accessibility Toolbar - www.paciellogroup.com/resources/wat-ie-about.html
Received on Wednesday, 5 December 2012 07:24:47 GMT

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