- From: Evain, Jean-Pierre <evain@ebu.ch>
- Date: Thu, 10 Mar 2011 09:53:26 +0100
- To: 'Pierre-Antoine Champin' <pierre-antoine.champin@liris.cnrs.fr>
- CC: "public-media-annotation@w3.org" <public-media-annotation@w3.org>
My late reading took me to the same general overview. Thanks for the synthesis. I agree completely. I'll do the changes (and run some tests too ;-) Regards, Jean-Pierre -----Original Message----- From: Pierre-Antoine Champin [mailto:pierre-antoine.champin@liris.cnrs.fr] Sent: jeudi, 10. mars 2011 09:33 To: Evain, Jean-Pierre Cc: public-media-annotation@w3.org Subject: Re: datatype properties' range Hi Jean-Pierre, just to make things clearer: the values of a datatype property are always "literals". However, in RDF, literals may have different forms: * they can have a language tag * they can have a datatype * they can have none of the two above * they can not have a language tag *and* a datatype the last two points are sometimes considered a design default in RDF, and will perhaps be fixed by the current RDF WG. But for the moment, only "untyped" literals can have a language tag. In OWL, the range of a datatype property specifies what kind of literal are expected as values of this property. If the range is a datatype (xsd:integer, xsd:date, xsd:string...), that will be typed literals with that datatype (and hence no language tag). If the range is rdfs:Literal, that will be untyped literals (hence possibily with a language tag). Datatypes like xsd:int or xsd:date bring some semantics compared to untyped literals. However, xsd:string has no added value: it has the same value space as untyped literals, but does not allow language tags. Hence my suggestion to : - replace xsd:string by rdfs:Literal for all datatype-properties having xsd:string, - keep all other range axioms untouched, as they add semantics (and language tags do not really make sense for integers, doubles or dates, anyway) I did a quick test: datatype with range rdfs:Literal do validate OWL-RL. pa On 03/09/2011 08:29 PM, Evain, Jean-Pierre wrote: > Pierre-Antoine, > > I am reading a lot of material on the use of rdfs:literal combined with xml:lang. I see all sort of opinions sometimes negative. > > Still, I guess if we go for literal it would need to be applied more systematically and not only to strings probably using typed literals?? > > Jean-Pierre > > -----Original Message----- > From: Evain, Jean-Pierre > Sent: mercredi, 9. mars 2011 19:31 > To: Evain, Jean-Pierre; 'Pierre-Antoine Champin'; public-media-annotation@w3.org > Subject: RE: datatype properties' range > > Pierre-Antoine, > > If I get you right you want to type the literal with a language or...? > > Regards, > > Jean-Pierre > > -----Original Message----- > From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Evain, Jean-Pierre > Sent: mercredi, 9. mars 2011 19:17 > To: 'Pierre-Antoine Champin'; public-media-annotation@w3.org > Subject: RE: datatype properties' range > > Pierre-Antoine, > > About changing 'xsd:string' to rdfs:literal. > > In this case would it be logical to make a similar change to datatype properties with e.g. integer content? > > There would also likely be a need to check compliance with OWL-RL or another profile, if we care? > > Regards, > > Jean-Pierre > > -----Original Message----- > From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Pierre-Antoine Champin > Sent: mercredi, 9. mars 2011 16:44 > To: public-media-annotation@w3.org > Subject: datatype properties' range > > Hi all, > > in the RDF ontology, all datatype properties with textual content have > range xsd:string. > > I think using rdfs:Literal instead would be beneficial, as we could > (optionally) add a language tag to those textual values. > > I mention it because the API document allows to attach a language > information to virtually any property value. This would be a nice way to > encode this in RDF as well. > > pa > > > ----------------------------------------- > ************************************************** > This email and any files transmitted with it > are confidential and intended solely for the > use of the individual or entity to whom they > are addressed. > If you have received this email in error, > please notify the system manager. > This footnote also confirms that this email > message has been swept by the mailgateway > ************************************************** ----------------------------------------- ************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. This footnote also confirms that this email message has been swept by the mailgateway **************************************************
Received on Thursday, 10 March 2011 08:54:18 UTC