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Re: Navigational features

From: Gez Lemon <gez.lemon@gmail.com>
Date: Sun, 4 Dec 2005 04:13:42 +0000
Message-ID: <e2a28a920512032013v1e3b887bo@mail.gmail.com>
To: "Bailey, Bruce" <Bruce.Bailey@ed.gov>
Cc: Guide Lines list <w3c-wai-gl@w3.org>

On 03/12/05, Bailey, Bruce <Bruce.Bailey@ed.gov> wrote:
>  As a point of reference, I have a bachelors degree in computer science from
> a decent school, and have been posting to the IG since at least 1998.  I
> regret that I have not sufficiently grokked the meaning behind
> "programmatically determined."  I find this a little a little frustrating,
> but perhaps it is just me?  In particular, how is that phrase differentiated
> from my second favorite gem, "parsed unambiguously"?

I think I may be able to help you with this one, Bruce. Both terms are
an attempt to be technology neutral, but parsed unambiguously goes a
step further in trying to avoid the words conformance or validity in a
guideline that at a glance might fool some people into believing that
validity and conformance might be best practice in adhering to that
guideline. Programmatically determined means that elements and
attributes can be programmatically extracted from the document
structure, whereas unambiguously parsed is an effort to acknowledge
that invalid content can choke user-agents, but avoids the word
validity at all costs.

The weakness of the term programmatically determined is that it's
defined to be technologically agnostic. The following is
programmatically determinable, but no known user agent would know what
to make of it:

<summary id="overview">The Importance of Being Valid</summary>

The weakness of unambiguously parsed is that it's meaningless. It
doesn't require that markup conforms to any kind of schema or DTD, or
that any other type of technology renders correctly in a user agent
that supports the technology; merely that the resulting data structure
is parseable.

The following snippet of HTML markup is not programmatically
determinable, as user agents wouldn't know what to do with it, as HTML
is well-defined. It can be parsed unambiguously, as the rules of
parsed unambiguously are non-existent, and any 999 experts would
conclude the same meaning.

<label for="day month year">Date:</label>

Best regards,


Supplement your vitamins
Received on Sunday, 4 December 2005 04:13:49 UTC

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