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Re: Is the ontology structure stored seamlessly with its data?

From: Ivan Herman <ivan@w3.org>
Date: Tue, 02 Oct 2007 17:18:27 +0200
Message-ID: <47026143.90803@w3.org>
To: "Luciano, Joanne S." <jluciano@mitre.org>
CC: Michael Schneider <schneid@fzi.de>, Emanuele D'Arrigo <manu3d@gmail.com>, Semantic Web Interest Group <semantic-web@w3.org>, "public-owl-dev-request@w3.org" <public-owl-dev@w3.org>

please, look at


for a bunch of tools in all kinds of languages. Although I did not make
a detailed survey of all the tools, I think the majority of the
toolkits/libraries do pretty much the same in relation to handling
ontologies and data.

I hope this helps


Luciano, Joanne S. wrote:
> Can anyone suggest a non-Jena / non-Java alternative?
> And for RDF (without OWL) also?  
> Thanks,
> Joanne 
>> -----Original Message-----
>> From: public-owl-dev-request@w3.org 
>> [mailto:public-owl-dev-request@w3.org] On Behalf Of Michael Schneider
>> Sent: Wednesday, September 26, 2007 1:37 PM
>> To: Emanuele D'Arrigo
>> Cc: Semantic Web Interest Group; public-owl-dev-request@w3.org
>> Subject: RE: Is the ontology structure stored seamlessly with its
> data?
>> Hi, Emanuele!
>> Emanuele D'Arrigo wrote at September 26, 2007:
>>> Another thing that is not quite clear in my mind right now is this:
>>> are the sets of triplets describing the class and property
> hierarchies
>>> of an ontology normally stored seamlessly alongside the data that
>>> is classified and characterized by those classes and properties?
>> With OWL, for which an RDF mapping exists, this is technically
> possible
>> without a problem. And when you, for instance, use JENA [1], a 
>> well known
>> RDF framework for Java, you generally /work/ with ontology 
>> based knowledge
>> bases in such a way (at least in principle). 
>> With JENA, you typically build a view to your knowledge base in the
>> following way:   
>>  1) Create a so called "Model", which is empty at the beginning
>>  2) Read into this Model the RDF statements representing the 
>> axioms of your
>> OWL ontology
>>  3) Read into this Model the RDF statements of your knowledge base
>> A "Model" in Jena represents an RDF graph, i.e. a set of RDF 
>> triples. Now,
>> as long as you use a pure "Model", this only gives you a view to the
>> combined set of RDF triples, which come from both your OWL 
>> ontology and your
>> knowledge base. But if you instead use an "OntModel" (which stands for
>> "Ontology Model"), you get an extended view to your RDF graph: 
>> Suddenly, you
>> have additional API functionality to access all your OWL classes and
>> properties, and the (explicit) sub-relationships between them (and
> many
>> other ontology specific features). The magic behind this is that the
>> OntModel internally separates out all those triple subsets within the
>> combind RDF graph, which are RDF mappings for OWL axioms. 
>> So this is the situation (or at least a possible and perfectly working
>> situation), when you /work/ with knowledge data. This does 
>> not, however,
>> mean that you should also /store/ ontological and assertional 
>> data together
>> in the same RDF graph. I think, in most cases it will be a 
>> better strategy
>> to have them separately stored. Then, you can easily reuse the 
>> ontology for
>> different knowledge bases, and combine them /on the fly/, 
>> whenever you want
>> to work with them.
>> Cheers,
>> Michael
>> [1] http://jena.sourceforge.net/ (JENA project page)
>> --
>> Dipl.-Inform. Michael Schneider
>> FZI Forschungszentrum Informatik Karlsruhe
>> Abtl. Information Process Engineering (IPE)
>> Tel  : +49-721-9654-726
>> Fax  : +49-721-9654-727
>> Email: Michael.Schneider@fzi.de
>> Web  : http://www.fzi.de/ipe/eng/mitarbeiter.php?id=555
>> FZI Forschungszentrum Informatik an der Universität Karlsruhe
>> Haid-und-Neu-Str. 10-14, D-76131 Karlsruhe
>> Tel.: +49-721-9654-0, Fax: +49-721-9654-959
>> Stiftung des bürgerlichen Rechts
>> Az: 14-0563.1 Regierungspräsidium Karlsruhe
>> Vorstand: Rüdiger Dillmann, Michael Flor, Jivka Ovtcharova, Rudi
> Studer
>> Vorsitzender des Kuratoriums: Ministerialdirigent Günther Leßnerkraus


Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf

Received on Tuesday, 2 October 2007 15:18:41 UTC

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