- From: Richard Cyganiak <richard.cyganiak@deri.org>
- Date: Fri, 4 Dec 2009 18:58:48 +0000
- To: Antoine Isaac <aisaac@few.vu.nl>
- Cc: Peter DeVries <pete.devries@gmail.com>, public-lod@w3.org, dmozzherin@gmail.com
Hi Antoine, So, can an rdfs:Class also be used as a skos:Concept, or vice versa? OWL DL folks will obviously not like this, but that's not my problem. A problem might be this: If there is a skos:Concept, and we use it as a class, what exactly are the instances of that class? Having this: foo:Cougar a skos:Concept; skos:prefLabel "Cougar". And then doing this: bar:Bob a foo:Cougar . Then Bob could be an animal, or Bob could be some sort of document, because the foo:Cougar concept may have been a "container" for documents rather than animals. So the "bar:Bob a foo:Cougar" triple really just tells us that bar:Bob is somehow related to or about cougars, but not that Bob is an animal of the species Cougar. This problem could be solved by saying that "foo:Cougar rdfs:subClassOf ex:Animal". So the problem can be worked around. But it still shows that using concepts as classes is tricky business. The other way round -- using classes as concepts -- seems safer. I find it hard to find a practical problem with this. Both for classes and for concepts there are custom properties for indicating equivalence -- owl:equivalentClass and the different skos:match properties -- so one can steer clear of owl:sameAs and avoid most of the usual coreference problems. Just random late-night thoughts ... Richard On 3 Dec 2009, at 18:58, Antoine Isaac wrote: >>> And in fact, while I understand that it is not very intuitive to >>> have Bob the cougar as a skos:Concept (even though it is >>> technically allowed), I see less problems for dealing this way >>> with the class of cougars... >> Mentioning that you see less problems without going into any detail >> is not exactly useful. I see more problems. > > Yes, I should have been clearer. > > In fact the most important argument (as I understand it from the > discussion you started at [1]) against considering a given entity as > a skos:Concept is that this entity may not have been designed as > part as a knowledge organization endeavour. It is for example rather > far-stretched to say that a person like Michelle Obama was conceived > as part of a knowledge organization system. > My point is that this is less problematic for classes, as these are > items of a knowledge organization system from the start. They are > also "taxonomist business objects", aren't they? So we could easily > treat them as skos:Concepts. > We have in fact touched this aspect in some parts of the SKOS > documentation [2,3,4]. I'd be very interested to know whether you > think this is wrong view! > > Best, > > Antoine > > [1] http://lists.w3.org/Archives/Public/public-esw-thes/2009Nov/0000.html > [2] http://www.w3.org/TR/2009/NOTE-skos-primer-20090818/#secskosowl > [3] http://www.w3.org/TR/skos-reference/#L896 > [4] http://www.w3.org/TR/skos-reference/#L1170 > > >>> >>> Best, >>> >>> Antoine >>> >>>> 2. I'm not sure if it's wise to use the same URI for the Cougar >>>> "concept" and the Cougar "class". I don't think that this >>>> "punning" is against any spec, but it will cause endless head- >>>> scratching among potential users of your data. It would be more >>>> straightforward to mint a separate URI for the class, and >>>> relating it 1:1 to the species concept using an appropriate >>>> property (there's probably one in UMBEL; if not, mint your own -- >>>> maybe "speciesClass"). Since you own the URI space anyway, >>>> minting new URIs would be cheap. >>>> This kind of punning between concepts, things and classes is an >>>> interesting issue, and I'm afraid that it's not yet well >>>> understood. Avoiding it puts you on the safe side. >>>> That being said, can you talk a bit about your motivation for >>>> wanting to re-use the same URI? >>>> Best, >>>> Richard >>>>> >>>>> This should work with OWL2 but I don't know how well it will >>>>> work with the >>>>> LOD. >>>>> >>>>> Also I created a VERY preliminary OWL document that would >>>>> contain a much >>>>> more complete representation of the species. >>>>> >>>>> My thoughts are that these OWL documents would be used to help >>>>> determine >>>>> what specimens are instances of what species concept. >>>>> The goal would be to provide an OWL document for those who need >>>>> a more >>>>> complete description of what we mean by the URI, while >>>>> also providing a much lighter RDF representation that could be >>>>> used for >>>>> concept mapping etc. >>>>> >>>>> However, I don't know if I am going about this in the right way. >>>>> >>>>> Below are my VERY preliminary examples of what these OWL >>>>> documents might >>>>> look like. >>>>> >>>>> The example has some attributes that I thought should be >>>>> included in a >>>>> species document, but it does not have everything that would >>>>> like to >>>>> eventually include. >>>>> >>>>> http://rdf.taxonconcept.org/owlses/v6n7p/2009-12-01.owl >>>>> >>>>> Doc's at http://rdf.taxonconcept.org/owlses/v6n7p/owl_doc/index.html >>>>> >>>>> The common classes etc, would eventually be moved to a separate >>>>> ontology >>>>> that would be imported into each individual species ontology. >>>>> >>>>> And these ontologies will need to be fixed so that they work >>>>> together, I >>>>> don't think they do right now. >>>>> >>>>> Thanks in Advance, :-) >>>>> >>>>> - Pete >>>>> ---------------------------------------------------------------- >>>>> Pete DeVries >>>>> Department of Entomology >>>>> University of Wisconsin - Madison >>>>> 445 Russell Laboratories >>>>> 1630 Linden Drive >>>>> Madison, WI 53706 >>>>> GeoSpecies Knowledge Base >>>>> About the GeoSpecies Knowledge Base >>>>> ------------------------------------------------------------ >>> > > -- Linked Data Technologist • Linked Data Research Centre Digital Enterprise Research Institute (DERI), NUI Galway, Ireland http://linkeddata.deri.ie/ skype:richard.cyganiak tel:+353-91-49-5711
Received on Friday, 4 December 2009 18:59:24 UTC