- From: Dan Brickley <danbri@danbri.org>
- Date: Wed, 19 Nov 2008 17:28:19 +0100
- To: Pierre-Antoine Champin <swlists-040405@champin.net>
- Cc: Semantic Web <semantic-web@w3.org>
Pierre-Antoine Champin wrote: > Dan Brickley a écrit : >> I do recommend against using RDFS/OWL to express application/dataset >> constraints, while recognising that there's a real need for recording >> them in machine-friendly form. In the Dublin Core world, this topic is >> often discussed in terms of "application profiles", meaning that we want >> to say things about likely and expected data patterns, rather than doing >> what RDFS/OWL does and merely offering machine dictionary definitions of >> terms. > > Why would you recommend against it? > > Would not a good practice be to simply separate in two RDF graphs > - "intensional" axioms, those representing the meaning of the terms > and that should be assumed by people reusing the vocabulary > - "extensional" axioms, those representing properties/constraints of > the dataset, that should be used to check its > consistency/completeness. > > Depending on their need, people would only import the first graph, or > both of them... I guess primarily because it is clearer for everyone if 'domain' and 'range' have their conventional meaning, rather than sometimes meaning what the W3C groups intended, and sometimes meaning something quite different. Since RDF is designed to mix and to flow, keeping the dataset-oriented usages separate is likely to be quite hard. Also I expect dataset-checking applications to have different requirements (eg. around optionals, co-occurance constraints, datatype values) that simply don't map tidily into RDFS/OWL constructs. Building on SPARQL there has some promise I think - eg see http://isegserv.itd.rl.ac.uk/schemarama/ http://swordfish.rdfweb.org/discovery/2001/01/schemarama/ On the dataset-characterisation front, there are also efforts like http://semwiq.faw.uni-linz.ac.at/node/9 that are worth exploring, also http://esw.w3.org/topic/SparqlEndpointDescription2 ... which are connected with scenarios around distributed SPARQL query. Again, I don't see RDFS/OWL's property-description constructs as being particularly attuned to this problem. cheers, Dan -- http://danbri.org/
Received on Wednesday, 19 November 2008 16:28:57 UTC