- From: Young,Jeff (OR) <jyoung@oclc.org>
- Date: Sat, 5 Mar 2011 13:40:05 -0500
- To: "Thomas Baker" <tbaker@tbaker.de>, <gordon@gordondunsire.com>
- Cc: <public-lld@w3.org>
I suspect the "over and above" takes us into Application Profile territory. Michael Panzer hinted at a Pellet-based solution for Application Profiles during the Joint DC2010/LLD XG meeting in Pittsburgh: http://www.w3.org/2001/sw/wiki/JointMeeting2010#Part_1_.2814:00-15:30.29:_Review_of_DCMI_Abstract_Model.2C_brainstorming_on_requirements c.f. http://clarkparsia.com/pellet/faq/closed-world/ This still seems feasible to me. A question that remains is where to draw the line for triples to be included in the graph before testing. Concise Bounded Description representations aren't adequate for this purpose, but a graph formed using rdfs:isDefinedBy could be. Here is an example, (with apologies to Gordon for using readable class names for FRBRer): <uri-1> a profile:FRBRerDoc . :expression/1 a frbrer:Expression; frbrer:isRealizationOf :work/1; rdfs:isDefinedBy <uri-1> . :work/1 a frbrer:Work; rdfs:isDefinedBy <uri-1> . Presumably an HTTP GET request for <uri-1> would deliver this graph independently of the CBD representations obtainable by doing HTTP GET requests on the individual URIs. Jeff > -----Original Message----- > From: public-lld-request@w3.org [mailto:public-lld-request@w3.org] On > Behalf Of Thomas Baker > Sent: Saturday, March 05, 2011 9:48 AM > To: gordon@gordondunsire.com > Cc: public-lld@w3.org > Subject: Re: Question about MARCXML to Models transformation > > Tom wrote: > > > On Tue, Mar 01, 2011 at 01:53:48PM +0000, Gordon Dunsire wrote: > > > > However, you need to think about the implications of using the > FRBRer, FRAD and > > > > FRSAD models. They have strong ontological constraints; for > example, an instance > > > > of the class frbrer:Expression requires the existence of an > instance of the > > > > class frbrer:Work (but not vice-versa). IFLA will publish an OWL > ontology for > > > > FRBR later this month (March 2011). > > > > > > A point of clarification... Do you mean that given an instance > > > of the class frbrer:Expression, one has license to _infer_ > > > the (theoretical) existence of an instance of the class > > > frbrer:Work -- even if that instance has not actually been > > > explicitly declared? > > > > > > Or does the model somehow require that for every instance of > > > Expression, an instance of Work must be explicitly declared? > > On Sat, Mar 05, 2011 at 10:57:57AM +0000, Gordon Dunsire wrote: > > There is a property restriction on the class Expression: > > > > frbrer:C1002 rdfs:subClassOf > > [ > > rdf:type owl:Restriction; > > owl:onProperty frbrer:P2002; > > owl:onClass frbrer:C1001; > > owl:qualifiedCardinality "1"^^xsd:nonNegativeInteger > > ]. > > > > (English labels: C1002 = "Expression", P2002 = "is realization of", > C1001 = > > "Work") > > > > I think this leads to the second of your interpretations: if an > instance of > > Expression, then 1 and only 1 instance of Work. > > > > There is a similar property restriction on the class Item ("is > exemplar of" 1 > > and only 1 Manifestation). The class Manifestation has a property > restriction > > ("is embodiment of" at least 1 Expression. > > Ah, but the nature of OWL is to describe "a reality", such > that given statements about the existence of certain things, > one has a license to infer statements about the existence of > other things. > > In this case, the restriction allows somebody, given an > instance of Expression, to infer the existence of one and > only one instance of Work -- my first interpretation with > the additional qualification of "one and only one". > > If the intention of the modelers is to force that inferred > Work to be declared explicitly in the data, there is nothing > in this OWL restriction that actually achieves or tests > for this. > > This brings us back to a point that arose early in our > discussions and is perhaps worth capturing, if it is not > already on our lists: the difference between the closed-world > assumptions underlying the creation of traditional library > formats, which enforce integrity constraints on the data > as it is expressed syntactically in record formats, versus > RDF/OWL modeling such as above. > > It relates to Dan's point that schema designers in the new > idiom are not actually issuing "shipping orders" for data > integrity in the imperative style to which they are accustomed > -- even if, as I suspect, they may sometimes _believe_ that > this is is the effect of declarations such as the above. > > As Jeff has pointed out, one might conceivably use the OWL to > construct syntactic validators to impose such data integrity, > but these are necessarily over and above whatever the OWL > itself actually says. > > Tom > >
Received on Saturday, 5 March 2011 18:41:00 UTC