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Re: RDF/XML shorthand for RDF reification

From: Ivan Herman <ivan@w3.org>
Date: Thu, 26 Jun 2008 11:32:46 +0200
Message-ID: <4863623E.5000903@w3.org>
To: Alan Ruttenberg <alanruttenberg@gmail.com>
CC: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, public-owl-wg@w3.org
I was actually surprised to see that Peter was right:-) I must admit 
that I thought myself that the rdf:nodeId could also be used in that 
position (generating a blank node for the reified statement) but, indeed,

http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-reifying

refers to rdf:ID only. Having said that (and that may be the reason) I 
do not think I have ever seen this rdf:ID+reification trick ever used in 
practice...

As both Alan and Peter said: this is independent on whether the reified 
triple should appear in the RDF graph explicitly or not. Actually (I am 
sorry Alan...) I do not think any RDF/XML syntax trick (whether there is 
a remedy or not) has any relevance here. Indeed, we should not rely on 
the particularities, oddities, etc, of one particular RDF serialization 
and we should keep to the RDF model. For the record, I believe Alan is 
right and we should have that extra triple in the graph; I saw no reason 
why we wanted to differentiate ourselves from RDFS/OWL Full semantics at 
that point...

Ivan

Alan Ruttenberg wrote:
> 
> 
> On Jun 25, 2008, at 3:50 PM, Peter F. Patel-Schneider wrote:
> 
>> The point I was making was that using the shorthand results in the
>> reification node having a real name, i.e., not being a blank node, which
>> messes up lots of things, including parsing and semantics.  Therefore,
>> arguments that rely on using the shorthand are not applicable, at least
>> without doing some investigation to see whether there is a remedy.
> 
> OK. I see this now. Good point. I'll poke around to see if there is a 
> remedy.
> 
> -Alan
> 
>>
>> This has nothing to do whether one would like to have the base triple or
>> not.
>>
>> peter
>>
>> From: Alan Ruttenberg <alanruttenberg@gmail.com>
>> Subject: Re: RDF/XML shorthand for RDF reification
>> Date: Wed, 25 Jun 2008 14:40:03 -0400
>>
>>> The point I was making is that it that I though that it was unreasonable
>>> for owl not to have the reified triple, and therefore this is well
>>> suited ;-)
>>>
>>> I also pointed out that it nullified the argument that there was an
>>> additional parsing burden to parse the "extra" actual reified triple. In
>>> effect the RDF/XML shorthand makes the parsing burden for a fully
>>> reified triple only slightly more than for the triple itself.
>>>
>>> -Alan
>>>
>>> On Jun 25, 2008, at 2:15 PM, Peter F. Patel-Schneider wrote:
>>>
>>>>
>>>> It appears to me that the RDF/XML shorthand for RDF reification creates
>>>> named reification, i.e., it names the reified triple.  I believe that
>>>> this means that its use is not reasonable for OWL.
>>>>
>>>> peter
> 
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf


Received on Thursday, 26 June 2008 09:33:26 GMT

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