W3C home > Mailing lists > Public > public-html-a11y@w3.org > August 2012

Re: Audience Based Validator User Interface (ISSUE-206)

From: Chaals McCathieNevile <w3b@chaals.com>
Date: Mon, 06 Aug 2012 16:48:44 +0500
Cc: "Laura Carlson" <laura.lee.carlson@gmail.com>, "Henri Sivonen" <hsivonen@gmail.com>, "Sam Ruby" <rubys@intertwingly.net>, "public-html@w3.org WG" <public-html@w3.org>, "HTML Accessibility Task Force" <public-html-a11y@w3.org>, "Michael[tm] Smith" <mike@w3.org>
To: "Benjamin Hawkes-Lewis" <bhawkeslewis@googlemail.com>, "Steve Faulkner" <faulkner.steve@gmail.com>
Message-ID: <op.wimjfil622x22q@chaals.local>
On Mon, 06 Aug 2012 13:44:49 +0500, Steve Faulkner
<faulkner.steve@gmail.com> wrote:

> Hi Ben,this would make more sense to me as it reflects reality,
> but as one tool vendor has commented, this would appear to entail all  
> HTML5 authoring tools including some form of built in >conformance  
> checking.

Yep. Conformance was an accessibility requirement when ATAG 1.0 was  
produced. It is not the highest one - since it may be that better  
accessibility can be provided by breaking it. Nonetheless, that meant that  
there was an effective requirement to provide conformance checking in  
authoring tools if they were going to be truly good at producing  
accessible content.

(Ensure the tool produces conformant markup). Priority 1 - the tools  
should get this right by default. HTML5 makes this easier in some  
important cases mentioned in this thread.

(do not auto-add e.g. alt=""). Priority 1. So Adobe is doing the right  
thing here. According to Steve's testing, so is Microsoft. Given that this  
stuff is over a decade old, that's not so surprising.

(allow the author to preserve unrecognised (e.g. invalid) markup).  
Priority 2 - you really should do this...

There are multiple libraries available for checking XML-based formats  
(e.g. XHTML which was the expected main format at the time), and there are  
libraries for HTML5. Henri is very smart, but presumably he isn't the sole  
person in the universe capable of writing tests for the machine-checkable  
aspects of HTML5 conformance...

Nothing forces tools to be perfect, but if they want to do so, surely they  
should actually provide the best possible service. As I understand it,  
Henri's objection to the meta generator stuff is because it stops him from  
doing so. The issue we seem to be dealing with here is that it is possible  
to create a 'pathological' test and thereby show that a tool is bad.

Maybe it is true that we should cope with this case. Interested parties I  
can see:
  + validator producers (who want to make their users happy)
  + authoring tool producers (who are worried by this test - apparently  
neither Microsoft nor Adobe are in practise)
  + authors (who will do anything, even break conformance with HTML, to  
look like they are conforming).

I'm unconvinced. Henri asked if people disbelieved the scenario posited as  
a problem. I by and large (there is an 80/20 split here because there are  
a lot of tools) disbelieve the scenario that tools are worried about  
validation of content they produce. The scenario of authors tweaking their  
content is less clear - and there are more authors so more scope for  
variation. But again I think it isn't so hard to get the majority of  
authors who care about validation to do The Right Thing™. And that is to  
leave out alt if they don't put a *valid* value - i.e. one relevant to the  
image in question.

This really boils down to social engineering - we're trying to trick  
people into doing the right thing, and failing that the least harmful  
thing we an get them to do. Which probably explains why smart people  
disagree on the best approach (it is not even entirely clear that we agree  
on how to order things that are not perfect in terms of relative badness).

In terms of finding consensus, I could probably live with the proposal for  
some kind of marker. I would object to it being a magic value for alt,  
which effectively leaves it as an attribute. (But what happens in the  
compound image case?) I also don't think there is much point in adding a  
huge long attribute name just to punish people who do a bad job. We  
already know they do a bad job, and making it hard for them to get  
anything right seems unlikely to encourage them to at least choose the  
"right" path.



> regards
> SteveF
> On 5 August 2012 20:25, Benjamin Hawkes-Lewis  
> <bhawkeslewis@googlemail.com> wrote:
>> On Sun, Aug 5, 2012 at 7:28 PM, Steve Faulkner  
>> <faulkner.steve@gmail.com> wrote:
>>> in any of the above a conforming HTML5 authoring tool would be useless  
>>> if it
>>> could not emit the documents.
>> Maybe we should say that a conforming HTML5 authoring tool MAY emit
>> "non-conforming HTML5 documents" but MUST make the author informed of
>> the (machine-assessable) conformance status of the document when
>> emitting.
>> --
>> Benjamin Hawkes-Lewis
> --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

Chaals - standards declaimer
Received on Monday, 6 August 2012 14:49:14 UTC

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