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RE: XHTML Applications and XML Processors [was Re: xhtml 2.0 noscript]

From: John Foliot <foliot@wats.ca>
Date: Wed, 2 Aug 2006 15:02:52 -0700
To: "'Jim Ley'" <jim@jibbering.com>
Cc: <www-html@w3.org>
Message-ID: <00b101c6b67f$69ca1130$e08240ab@Piglet>

Jim Ley wrote:
> Proves the statement?  I could show you (with appropriate NDA's and
> agreement from 3rd parties) plenty of user testing that shows users
> start 
> interacting with any control as soon as they are able, 

Fair enough, but if you are required to use a screen reading technology that
requires this, it generally in fact requires that the whole page downloads
first.  Perhaps you have not read the article from the link that I provided
in my earlier post
but I will quote from Gez's article:

"To allow screen reader users to read and interact with web content, screen
readers take a snapshot of the web page, and place this content in a virtual
buffer. The screen reader uses the virtual buffer to allow the user to
navigate the content. Without the virtual buffer, the screen reader only has
access to the parts of the page that are focusable by non-assistive user
agents, such as anchors and interface elements. Without the virtual buffer,
the user cannot interact with other elements and their child nodes in the
content, such as images, lists, tables, and so on."

Unless I am completely off base here, this effectively means that AT users
require the full document to download so that their AT software can then
further process the information.  The visual users in your NDA protected
"research" - how many of them used assistive technology?  And more
importantly, given the above information, should it not be taken into
consideration as this discussion moves forward?

> it matters not
> if "the whole document has downloaded" - that's simply not a concept
> the users 

[sighted users?]

> understand, they interact with things as soon as they are able - so
> as soon 
> as they are shown it, no matter how they are shown it.  

Right, and for screen reader users, this is after the document has
completely loaded - that's how they are "shown" it. Developers may not
*like* this fact, but for non-visual users that rely on Adaptive Technology
(and not just play with it in the testing lab) this linear content cognitive
model is the only one they have... That's just the way it is.
Programmatically, you may in fact be clever enough to do things that ignore
this fact, but just because you can, should you?  And so I frame it in the
context of *that* question.  (And yes, I know that this is the HTML list and
not the WAI-IG list... But if you haven't been over to that list in a while,
you should stop by and visit <smile>)

> So a screen user reader would expect a 1mb document to be fully
> downloaded 
> before it even started to read the first line? 

Not so much expect, but accept... That's simply the way their software works
- they don't actually get a choice.

> I am astonished to
> believe 
> that, surely they, like anyone else want to get to the content as
> soon as 
> possible, 

Right, so don't post 1 mb documents!  (WCAG 1, Priority 2 - 12.3 Divide
large blocks of information into more manageable groups where natural and

> why would they want to wait, simply to be told "XHTML
> Applciations 
> and XML processors" etc.

Trust me Jim... They don't want to wait any longer than you would.  They
have the added burden of *having* to wait, just to discover the wait was for
nothing.  Let's not add to that burden.

Received on Wednesday, 2 August 2006 22:03:14 UTC

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