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Re: looking for an event ontology/vocabulary

From: Bernhard Haslhofer <bernhard.haslhofer@univie.ac.at>
Date: Thu, 30 Jul 2009 16:14:50 +0200
Cc: public-lod@w3.org
Message-Id: <B31B94D2-62AF-47E7-A642-016F679E276F@univie.ac.at>
To: Simon Reinhardt <simon.reinhardt@koeln.de>
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

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Received on Thursday, 30 July 2009 14:15:27 UTC

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