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Re: question about OWL-S and XML Schema version

From: David Martin <martin@ai.sri.com>
Date: Wed, 16 Jul 2003 04:09:49 -0700
Message-ID: <3F15327D.9070302@ai.sri.com>
To: Jos de Bruijn <jos.de-bruijn@uibk.ac.at>
CC: "Terry R. Payne" <trp@ecs.soton.ac.uk>, "'Grit Denker'" <Grit.Denker@sri.com>, www-ws@w3.org

I agree with Jos' perspective on this.

- David

Jos de Bruijn wrote:

> Dear all,
>
> I have looked at the schema at 
> http://www.w3.org/2001/XMLSchema-datatypes.xsd and all it does is take 
> data types from the http://www.w3.org/2001/XMLSchema namespace and put 
> them in the http://www.w3.org/2001/XMLSchema-datatypes namespace. So 
> the correct namespace would still be http://www.w3.org/2001/XMLSchema.
> It makes no sense for a reasoning engine to retrieve a schema for 
> XMLSchema. The schema should be expressed in another schema language 
> and we can keep on going.
> The reasoning engine should have built-in support for XMLSchema. This 
> is what is assumed when the http://www.w3.org/2001/XMLSchema is used. 
> A reasoning engine for daml is also assumed to have the knowledge to 
> cope with daml. It cannot depend on the retrieval of a schema for daml.
>
> Best,
>
> Jos de Bruijn
>
> Terry R. Payne wrote:
>
>>Dave,
>>	I just looked at this (I didn't check with my recent spate of
>>changes) and indeed there could be a problem, specifically as this URL
>>refers to just the html of a doc.
>>
>>A little digging reveals that the schema itself is in [1]
>>
>>[1] http://www.w3.org/2001/XMLSchema-datatypes.xsd
>>
>>But the issue is that of what it means to resolve a URL and a namespace.
>>Many people (including myself) work on the (broken) assumption that URLs
>>can be resolved and the information retrieved by a simple http request.
>>It's not totally valid, but works for now.
>>
>>Looking at the schema, it does define the namespace to be
>>http://www.w3.org/2001/XMLSchema, but this presupposes that your
>>reasoning engine has already retrieved the schema definition in [1] that
>>defines this namespace... Ah, but on closer inspection, the
>>targetNamespace defined in [1] is:
>>
>>[2] http://www.w3.org/2001/XMLSchema-datatypes
>>
>>i.e. the schema URL minus the extension!
>>
>>I'm never sure what the exact difference of default namespace and target
>>namespace is, so unless anyone can clarify off the top of their head,
>>I'll investigate.
>>
>>I suspect that we should probably change the namespace in the daml-s
>>docs to either [1] or [2]...
>>
>>	Terry
>>
>>
>>_______________________________________________________________________
>>Terry R. Payne, PhD.      | http://www.ecs.soton.ac.uk/~trp/index.html
>>University of Southampton | Voice: +44(0)23 8059 8343 [Fax: 8059 2865]
>>Southampton, SO17 1BJ, UK | Email: terry@acm.org / trp@ecs.soton.ac.uk
>>
>>
>>
>>
>>  
>>
>>>-----Original Message-----
>>>From: www-ws-request@w3.org [mailto:www-ws-request@w3.org] On Behalf
>>>    
>>>
>>Of
>>  
>>
>>>David Martin
>>>Sent: 16 July 2003 00:11
>>>To: Grit Denker
>>>Cc: www-ws@w3.org
>>>Subject: question about OWL-S and XML Schema version
>>>
>>>
>>>[Note: the original message wasn't posted on www-ws.]
>>>
>>>Grit Denker wrote:
>>>
>>>    
>>>
>>>>Hi All,
>>>>
>>>>we tried to load the latest version of Process.daml into our
>>>>DAML+OIL-plugin for Protege and ran into
>>>>
>>>><daml:DatatypeProperty rdf:ID="invocable">
>>>> <rdfs:comment>Invocable is a flag that tells whether the
>>>>CompositeProcess
>>>>bottoms out in atomic processes. (If so, it is
>>>>"invocable".)</rdfs:comment>
>>>> <rdfs:domain rdf:resource="#CompositeProcess" />
>>>> <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#boolean"
>>>>      
>>>>
>>/>
>>  
>>
>>>></daml:DatatypeProperty>
>>>>
>>>>The referenced range does not (yet) seem to be fully defined (the web
>>>>page hardly contains any information yet).
>>>>Is this a bug or a reference to upcoming XMLSchema?
>>>>Shouldn't the range resource be
>>>>http://www.w3.org/2000/10/XMLSchema#boolean?
>>>>That would at least have substantial definitions.
>>>>
>>>>Could somebody please clarify this for me? We would like to know
>>>>whether we need to extend our plugin.
>>>>
>>>>      
>>>>
>>>Hi Grit -
>>>
>>>With the latest release (0.9) of DAML-S/OWL-S, we changed the
>>>    
>>>
>>XMLSchema
>>  
>>
>>>namespace to
>>>
>>>http://www.w3.org/2001/XMLSchema
>>>
>>>as you have noticed.
>>>
>>>This was done at the suggestion of a knowledgable user who said it
>>>    
>>>
>>would
>>  
>>
>>>make life much easier for him, and also because it seemed obvious that
>>>we should employ the most recent completed release.
>>>
>>>I'm not really an expert on XML Schema, but I believe this namespace
>>>does represent the most recent completed release.  If that's not
>>>correct, someone please respond with the correct info.
>>>
>>>I don't know why the document at http://www.w3.org/2001/XMLSchema_ _
>>>is so impoverished.  But it is my impression that that's the correct
>>>namespace to use.  Take a look at the document here:
>>>    http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/datatypes.html
>>>for better documentation of the datatypes.  Note that this document
>>>references the above namespace.
>>>
>>>Finally, I must admit I never considered whether this change would
>>>affect the work on the plugin.  The only resulting change we made in
>>>DAML-S/OWL-S files was this:
>>>   changing uriReference to anyURI.
>>>
>>>Regards,
>>>David
>>>    
>>>
>>
>>
>>
>>  
>>
>
>-- 
>Jos de Bruijn
>
>Institute of Computer Science
>University of Innsbruck
>Technikerstraße 13
>A-6020 Innsbruck
>Austria
> 
>Tel:      +43 512 507 6475
>Fax:      +43 512 507 9872
>Email:    jos.de-bruijn@uibk.ac.at
>Homepage: http://homepage.uibk.ac.at/~c703239/
>
>Next Web Generation research group
>http://www.nextwebgeneration.org/
>
Received on Wednesday, 16 July 2003 07:10:47 GMT

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