W3C home > Mailing lists > Public > www-qa@w3.org > September 2003

[qaframe-spec] conformance tools vs. broken specs

From: Bjoern Hoehrmann <derhoermi@gmx.net>
Date: Mon, 01 Sep 2003 06:07:58 +0200
To: www-qa@w3.org
Message-ID: <3f9ab490.140875568@smtp.bjoern.hoehrmann.de>


  If you submit a web page address to the W3C MarkUp Validator, it could
happen that the result page tells you that your document is "Valid XHTML
1.0 Strict" and provides a link to the XHTML 1.0 Recommendation. If you
follow this link you will encounter a problem: There is no definition of
what it means for a document to be identified as "Valid XHTML 1.0
Strict". This is an important issue for web authors and tool developers
who care about web standards and I think the current Specification
Guidelines draft does not sufficiently address it.

There are people in the web authoring commuity who claim that it is
obvious what it means for a document to be "Valid XHTML 1.0 Strict";
"Valid" is defined in the XML 1.0 recommendation and "XHTML 1.0 Strict"
is the XHTML-1.0-Strict DTD as defined in Appendix A.1 of the XHTML 1.0
Recommendation. I disagree with them. I think it is reasonable to expect
that if a document violates requirements of the XHTML 1.0 specification
that it cannot be considered a XHTML 1.0 document no matter whether it
fullfills the requirements for beeing considered a "valid" XML 1.0
document. Others introduce a notion of "valid but not conforming" which
is getting a permathread on mailing lists and newsgroups. I wouldn't
mind if they call it "Valid XML 1.0 document but not Strictly Conforming
XHTML 1.0 document" but they follow the W3C Validator's lead and call it
"Valid XHTML 1.0 Strict but not Strictly Conforming XHTML 1.0".

This interpretation hinders me as a tool developer to reuse the term, if
my document conformance testing tool is able to test for constraints
which are not expressed/expressable in the DTD I can either choose to
emit errors *and* identify the document as beeing "valid" which would
confuse users as they understand Validity as the absence of errors, or I
can identify the document as beeing invalid which would confuse users as
my tool considers documents invalid which the in their eyes official and
only normative tool, the W3C Validator, considers valid. I could choose
different terminology but there are no appropriate defined terms and
even if there were they would have worse usability than "valid".

The situation will get worse if W3C publishes specifications that define
multiple normative schemas. You could get FooML documents that are valid
under the XML 1.0 DTD definition of "valid", valid under the W3C XML
Schema 1.0 definition of "valid" but still not conforming FooML

I would really appreciate if all W3C specifications defining a notion of
instance data are explicitly required to identify all programmatically
reportable errors, make reporting these a requirement for a specific
class of product, define how to identify such software and define how to
identify instances which do not have reportable errors.

XML 1.0 is a good example that fullfills these requiremements, 

  * reportable errors are identified trough "well-formedness
    constraints" and "validity constraints"

  * documents that meet the well-formedness constraints are identified
    as "Well-formed XML 1.0 documents"

  * documents that meet the "validity constraints" are identified as
    "Valid XML 1.0 documents"

  * software that reports violations of well-formedness constraints is
    identified as "XML 1.0 processor"

  * software that reports violations of validity constraints is
    identified as "Validating XML 1.0 processor"

It would be even better if XML 1.0 had conformance requirements (or at
least a definition of the term) "XML 1.0 Validator"...

This is just a terminology issue but good terminology is **vital** for
understanding, discussing, and advertising technology. Beeing involved
in both, the XML and web authoring community, I never had to waste my
time arguing about what consitutes a well-formed XML document but today
no week passes by without a argument about what a valid/conforming/
strictly conforming/whatever HTML/XHTML document is and this is nothing
but hair-raising.

Received on Monday, 1 September 2003 00:08:25 UTC

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