- From: Bernhard Haslhofer <bernhard.haslhofer@univie.ac.at>
- Date: Thu, 30 Jul 2009 16:14:50 +0200
- To: Simon Reinhardt <simon.reinhardt@koeln.de>
- Cc: public-lod@w3.org
we have been working with the CRM in the past so I feel like commenting on that: On Jul 30, 2009, at 2:53 PM, Simon Reinhardt wrote: > Richard Light wrote: >> Another ontology/vocabulary which is centred around events is the >> CIDOC CRM (Conceptual Reference Model). [1] It is "a formal >> ontology intended to facilitate the integration, mediation and >> interchange of heterogeneous cultural heritage information", and >> comes out of the museums community. There is an OWL representation >> [2] which has been developed by a group at Erlangen-Nuremburg >> University. It certainly doesn't lack definitions ;-) >> I would be interested to hear what Linked Data folks make of it as >> a potential framework for expressing more general event-related >> assertions, i.e. going beyond its stated scope. I would also value >> a more expert opinion than my own as to whether the current >> expression of the CRM (either the OWL or RDF [3] version) is "fit >> for purpose" as a Linked Data ontology. The CRM is kind of a global ontology for the cultural heritage domain, which is great because it summarizes (and formalizes) many of the notions and terms used in that domain. From a practical (I guess this is more the Linked Data perspective) point of view its application is however a bit problematic: the concepts it defines often have very abstract definitions which leave lots of room for interpretation. So it happens quite easily that things are mixed up when data are mapped to the CRM (at least from our experience) - which is bad from an interoperability perspective. This problem could be solved by defining a new vocabulary for your application context which refines the CRM concepts with more precise definitions. The second problem we have encountered is that in CRM expressing even very simple assertions requires to build up quite complex so-called "CRM chains"; this is because the CRM defines mostly concepts (classes) and relationships (object properties) but hardly provides any fields for capturing the actual data. Furthermore, these chains make it extremely complex to process and query the data on the application level - so it is not really suitable for the LOD context. At least it was like that approximately 1-2 years ago...maybe it has changed meanwhile...need to catch up on that. > > I'm certainly no expert. :-) But I think CIDOC-CRM in it's current > RDF versions is a bit problematic from a Linked Data POV. The OWL > representation [2] has the wrong content type (this is certainly > something that can be fixed) and it doesn't have a stable namespace > (the term URIs are all relative to the current OWL file). As far as > I can see, the way the identifiers are built they cannot be > abbreviated in Turtle either. And I'm not happy with the definition > of inverse properties. I started manually converting the CRM into > OWL (using some OWL 2 constructs like versionIRI and property chains > as well) and under a stable purl.org namespace [4]. I'm not done > with the properties yet but you can retrieve Turtle and RDF/XML > versions and get an idea of what it looks like. Agree. As I said, with the version we were working with, we had big troubles when expressing even very simple assertions in RDF. So my advice for the LOD context: keep it simple and try to find another vocabulary/ontology or refine an existing one. Best, Bernhard > > Regards, > Simon > >> [1] http://cidoc.ics.forth.gr/ >> [2] http://www8.informatik.uni-erlangen.de/IMMD8/Services/cidoc-crm/index.htm >> l >> [3] http://cidoc.ics.forth.gr/rdfs/cidoc_crm_v5.0.1.rdfs > > [4] http://purl.org/NET/cidoc-crm/core > ______________________________________________________ Research Group Multimedia Information Systems Department of Distributed and Multimedia Systems Faculty of Computer Science University of Vienna Postal Address: Liebiggasse 4/3-4, 1010 Vienna, Austria Phone: +43 1 42 77 39635 Fax: +43 1 4277 39649 E-Mail: bernhard.haslhofer@univie.ac.at WWW: http://www.cs.univie.ac.at/bernhard.haslhofer
Received on Thursday, 30 July 2009 14:15:27 UTC