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Re: Re : Influence of valid code on screen readers

From: Tina Holmboe <tina@greytower.net>
Date: Sat, 18 Jun 2005 23:10:05 +0200 (CEST)
Message-Id: <200506182110.j5ILA5FU006315@asterix.andreasen.se>
To: w3c-wai-gl@w3.org

On 18 Jun, Maurizio Boscarol wrote:

> Still, that will not guarantee accessible pages. It depends on quality 
> of code, of textual equivalents, of structural and semantic markup,
> and many other design solutions.

  Here's the catch. A valid document may, just as an invalid one, be
  accessible. However, an *invalid* one runs a much greater risk of
  having *poor* structure and mangled semantics.

  We all agree, I would presume, that structure and semantics are
  important pieces of accessibility. Valid code is essential: if the
  structure and semantics are coded *wrong*, then who knows what might
  come out in the other end of a random user-agent?

  Invalidity equals poor quality code, possibly incorrect structure, and
  the chance of confusing semantics. Whyever would we NOT want to make
  this a priority one checkpoint?

> the problem about validation isn't always tag soup, but some little 
> implementation mistakes, that don't significatively affect the quality 
> of code. The pages can nonetheless be accessible.

  The problem we would need to accept is rather this: there is no way to
  tell whether the "little implementation mistake" is, or is not, a
  problem for accessibility.

  As you write:

> a good indicator of quality, but even minor problems in validity
> don't affect accessibility.

  Perhaps not. And perhaps they do. However, *major* problems with
  validity *do* affect accessibility.

  In reality, there is no way to tell which of these little mistakes
  might have an effect or not, without actual testing.

  The only sensible way of handling this situation is to state, clearly:
  validity issues that can be automatically tested, SHOULD be
  automatically tested as a priority one checkpoint and, in effect,
  gotten out of the way.

  Otherwise we need to add something to p1 which says: "Make sure any
  invalid code doesn't mess up accessibility".

  As has been pointed out - we cannot *know* that invalidity
  messes with accessibility. The flip side is that we cannot *know* that
  it doesn't, not without testing.

  Testing to see whether doing things incorrectly might create
  accessibility problems is somewhat illogical.

> complain about validation, but only about real accessibility.
> Validation should be encouraged, but at the top quality level, not at
> basic level.

  Invalid structure and semantic is, atleast in my mind, as real an
  accessibility issue as any.

  Besides, it *is* an easy problem to fix.

 -    Tina Holmboe                    Greytower Technologies
   tina@greytower.net                http://www.greytower.net/
   [+46] 0708 557 905
Received on Saturday, 18 June 2005 21:10:13 UTC

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