- From: Antoine Isaac <aisaac@few.vu.nl>
- Date: Wed, 22 Aug 2012 21:15:17 +0200
- To: <public-lod@w3.org>, SKOS <public-esw-thes@w3.org>
Dear Thomas, I'm ccing public-esw-thes@w3.org. Perhaps this was the one you were looking for! (1) & (2) You probably mean, if a ConceptScheme could be defined as a class, of which the concepts of a given concept scheme are instances? That would be the way to proceed, if you want to use the concept scheme directly as the range of a property. This is has never been suggested for inclusion in SKOS. In fact it is not forbidden, either. You can assert rdf:type statements between concepts and a concept scheme, if you want. You can also define an adhoc sub-class of skos:Concept (say, ex:ConceptOfSchemeX), which includes all concepts that related to a specific concept scheme (ex:SchemeX) by skos:inScheme statements. This is quite easy using OWL. And then you can use this new class as the rdf:range. The possibility of these two options makes it less obvious, why there should be a specific feature in SKOS to represent what you want. But more fundamentally, it was perhaps never discussed, because it's neither a 100% SKOS problem, nor a simple one. It's a bit like the link between a document and a subject concept: there could have been a skos:subject property, but it was argued that Dublin Core's dc:subject was good enough. But it's maybe even worse than that :-) There are indeed discussions in the Dublin Core Architecture community about represent the link between a property and a concept scheme directly, similar to what you want. This is what is called vocabulary/value "encoding schemes" there [1]. But the existence of this feature at a quite deep, data-model level, rather confirms for me that it is something that clearly couldn't be tackled at the time SKOS was made a standard. One can view this problem as one of modeling RDFS/OWL properties, rather than representing concepts, no? (3) I'm not sure I get the question. If they exist, such mapping properties could be very difficult to semantically define. Would a concept scheme be broader, equivalent, narrower than another one? Rather, I'd say that the property you're after indicates that some concepts from these two concept schemes are connected. For this I think one could use general linkage properties between datasets, such as voiD's linksets [2]. I hope that helps, Antoine [1] http://dublincore.org/documents/profile-guidelines/ , search "Statement template: subject" [2] http://vocab.deri.ie/void ------- This is about SKOS usage in LOD. Yesterday I sent a post to public-swd-wg@w3.org, but obviously it has not been distributed, although it can be found in the archive. http://lists.w3.org/Archives/Public/public-swd-wg/2012Aug/0000.html public-swd-wg@w3.org isn't very active any more, so public-lod@w3.org might be a better place. Best regards, Thomas -------- Original-Nachricht -------- Betreff: referencing a concept scheme as the code list of some referrer's property Datum: Sun, 19 Aug 2012 10:50:05 +0200 Von: Thomas Bandholtz <thomas.bandholtz@innoq.com> An: public-swd-wg@w3.org Hi SKOS, I came across several examples where concept schemes are referenced as the code list of some property. Usually this is done by two statements: ex:property rdfs:range skos:Concept ; ex:codeList < [some concept scheme] > . E.g. Data Cubes and geonames use this pattern, but one uses qb:codeList to point to the scheme, the other gn:featureClass. Regarding this, I have two questions: (1) does someone remember a discussion why concept schemes should not be expressed as subclasses of skos:Concept? If subclassing would have been used, any concept scheme could be referenced in a single rdfs:type statement of the concept and a single rdfs:range statement of the referrer. (2) if there are sufficient reasons to insist in the current patterns, shouldn't SKOS be extended by a standard property to be used by referrers when they point to a concept scheme along with a rdfs:range statement? And I add (3) why do we not have mapping properties to link concept schemes from different providers? This cannot be inferred from a given concept mapping, as mapping of some concepts does not imply mappings of their entire schemes. Best regards, Thomas -- Thomas Bandholtz Principal Consultant innoQ Deutschland GmbH Krischerstr. 100, D-40789 Monheim am Rhein, Germany http://www.innoq.com thomas.bandholtz@innoq.com +49 178 4049387 http://innoq.com/de/themen/linked-data (German) https://github.com/innoq/iqvoc/wiki/Linked-Data (English)
Received on Wednesday, 22 August 2012 19:15:48 UTC