- From: Graham Klyne <GK@ninebynine.org>
- Date: Tue, 19 Feb 2002 11:24:26 +0000
- To: "David Orchard" <david.orchard@bea.com>
- Cc: "'TAG'" <www-tag@w3.org>
I think this pinhead-angel-counting has an important purpose beyond arguing about the meaning of "schema", viz that one might reasonably want to use a namespace URI to associate both syntactic and interpretive definitional material with a document. I take that to be the substantive point behind the discussion so far. #g -- At 02:29 PM 2/18/02 -0800, David Orchard wrote: >This is starting to get discouraging. I find it amazing that the TAG cannot >get to consensus on what a schema is, even though it is used in different >specifications at the W3C and the W3C even has an XML Schema language. > >I believe we must solve this definition problem and document this in our >arch document. We obviously have 2 camps: >1) schemas are syntactic validation, and dtds/xml schema/relax/dcd/WSDL are >instances. >2) schemas are any kind of definition used in interpretation. This includes >1) but adds in html, RDF Schema, others. A fragment from RDF Schema >illustrates "Unlike an XML DTD or Schema, which gives specific constraints >on the structure of an XML document, an RDF Schema provides information >about the interpretation of the statements given in an RDF data model. " > >For point of information, I did a quick survey internally and every single >developer that I talked in my company found option #1 to be correct, and >option #2 to be a non-helpful definition. The re-inforcement of this >position was pointed out in the very name of "XML Schema", which talks about >syntactic constraints. A developer asked about the difference between >definition #2 of schema and the term metadata, to which I didn't have an >answer. I venture that every developer in my company and probably almost >all of our > 10 000 customers consider #1 to be the correct definition. > >I briefly thought that we could define 2 sub-types of schema languages, >something like: syntactic schema and interpretive/semantic/? schema. I also >ran this separation by our developers. The response was one of disbelief >that the TAG was even spending time on this when the "real" answer was so >obvious and one developer joked about counting angels on pin heads. All >this reaffirmed my earlier position on the definition of schema. > >Is there any possibility that the proponents of option #2 could see their >way to adopting schema definition #1? I would volunteer to help with coming >up with a new term for #2. > >Maybe I'm being naive that we can make progress on this, but it seems >important to be precise and also obey the least-astonishment rule. > >Cheers, >Dave > > > > -----Original Message----- > > From: www-tag-request@w3.org > > [mailto:www-tag-request@w3.org]On Behalf Of > > Tim Bray > > Sent: Monday, February 18, 2002 1:51 PM > > To: TAG > > Subject: [namespaceDocument-8] 14 Theses, take 2 > > > > > > During the TAG telecon this morning, there was some discussion > > of my theses on namespace documents. Someone made the wild claim > > that there was consensus on most points, which to be fair seems > > a little unlikely since they had been published for considerably > > less than 12 hours at the time. > > > > Having said that, Paul Cotton had an issue with thesis 7 "Definitive > > material is normally distributed among multiple resources", offering > > the counter-example of "lightweight" namespaces he and colleagues > > routinely cook up for a list of words or the functions in an API > > or something, that typically only come with a chunk of text. > > Seems fair; I redrafted section 7 to acknowledge this case. [I > > don't think it weakens the arguments for any of the following theses]. > > > > Several people had trouble with thesis 14 "Namespace documents > > should not be schemas"; mostly it seemed, based on lack of agreement > > as to what a schema is or should be. I've redrafted that one to > > make it clear that we're talking about the mostly-syntactic schemas > > of today (e.g. DTDs, XML Schemas), what the world calls schemas > > today - and put the word "schemas" in quotes in the thesis statement. > > > > Finally, Dan Connolly had an issue with Thesis 13 "Namespace > > documents should not favor the needs of any one application or > > application class" which I never got time to understand. Dan? > > -Tim > > > > ------------ Graham Klyne GK@NineByNine.org
Received on Tuesday, 19 February 2002 06:56:21 UTC