- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Fri, 12 Sep 2008 11:45:37 -0400
- To: "Boris Motik" <boris.motik@comlab.ox.ac.uk>
- Cc: "Michael Schneider" <schneid@fzi.de>, "W3C OWL Working Group" <public-owl-wg@w3.org>
On Fri, Sep 12, 2008 at 11:30 AM, Boris Motik <boris.motik@comlab.ox.ac.uk> wrote: > Hello, > > The concept of a datatype map is there just to act as a container for all datatypes. Please note that this notion has been taken > from OWL 1. Hence, instead of explaining why we removed it in OWL 2, we might as well use it. Furthermore, I find this notion quite > useful and don't see how eliminating it would make the documents easier to understand: instead of saying "the set of supported > datatypes", we say "a datatype map". That seems shorter, and it is also quite useful for the Semantics document(s). Saying *the* datatype map corresponds to "the set of supported datatypes". Saying *a* datatype map suggests that a conformant OWL implementation might have a different one. -Alan > > Regards, > > Boris > >> -----Original Message----- >> From: public-owl-wg-request@w3.org [mailto:public-owl-wg-request@w3.org] On Behalf Of Alan Ruttenberg >> Sent: 12 September 2008 16:13 >> To: Michael Schneider >> Cc: W3C OWL Working Group >> Subject: Re: Question about datatype maps >> >> >> On Fri, Sep 12, 2008 at 7:02 AM, Michael Schneider <schneid@fzi.de> wrote: >> > Hi Alan! >> > >> > Alan Ruttenberg wrote: >> > >> >>The OWL specification has a datatype map as a parameter. It's unclear >> >>to me what are allowable extensions in the realm of datatypes, and >> >>whether such extensions would be desirable from an interoperability >> >>point of view. Now that we have a wide range of datatypes, do we need >> >>to support extensibility here? Our experience OWL 1, OWL 2, that >> >>choice and semantics of datatypes are not a slam-dunk obvious choice, >> >>raising questions about whether sanctioned extensions to OWL in this >> >>dimension would be beneficial or cause more trouble than they are >> >>worth. Of course nothing would prevent unsanctioned extensions - my >> >>question here is of what we should encourage. >> >> >> >>-Alan >> > >> > I simply would not say anything. Of course, we cannot forbid that >> > implementers support additional datatypes. And custom datatypes, such as >> > complex numbers, will make sense and add value in certain domains. Interop >> > is then given by the OWL 2 spec: As long as an ontology only uses those >> > datatypes, which are defined in the OWL 2 spec, no problems will arise with >> > reasoners that /at least/ support all these OWL 2 datatypes [1]. If, >> > however, an ontology uses additional datatypes, all bets are off; but why >> > should we care as a WG? That's then in the responsibility of those who >> > create and use such ontologies (they have to settle on a certain reasoner, >> > etc.). >> >> Well, this is kind of my point. We are currently saying *something*. >> Why mention the concept of datatype map at all, instead of just >> documenting the datatypes? Currently datatype maps are mentioned in >> virtually all the documents. Wouldn't removing discussion of it and >> instead only talking about datatypes make those documents shorter (at >> least marginally) and easier to understand? >> >> -Alan >> >> >> > >> > Btw, the RDF Semantics document introduced datatype maps years ago, stating >> > in [2]: >> > >> > "RDF provides for the use of externally defined datatypes >> > identified by a particular URI reference. >> > In the interests of generality, RDF imposes minimal >> > conditions on a datatype. It also includes a single >> > built-in datatype rdf:XMLLiteral." >> > >> > So supporting external datatypes beyond those shipped with the standard was >> > clearly intended. >> > >> > Cheers, >> > Michael >> > >> > [1] >> > <http://www.w3.org/2007/OWL/wiki/Semantics#Independence_of_the_Semantics_fro >> > m_the_Datatype_Map> >> > [2] <http://www.w3.org/TR/rdf-mt/#dtype_interp> >> > >> > > > >
Received on Friday, 12 September 2008 15:46:18 UTC