RE: FOAF DL

Hi!

One note of caution!

The FOAF-DL ontology is only (approximately) equivalent to the original
version of FOAF in OWL /2/, since OWL keys have only been introduced as of
OWL 2. Older existing systems that depend on the FOAF inverse-functional
data properties (IFDPs) have to make sure that they can also work with the
new OWL 2 keys, before switching to the FOAF-DL ontology. 

If such a system internally uses a reasoner that is able to work with IFDPs
but does not know about OWL 2 keys (e.g. the current version of the Jena
rule reasoner), then the system will not be able to make the expected
inferences anymore, i.e. that two foaf:Person having the same mbox_sha1sum
are the same person. So one will have to decide to either stay with the old
FOAF ontology, or to replace the currently used reasoner.
 
This is, of course, a general problem when trying to upgrade to a newer
specification. But it should at least be stated explicitly, when publishing
a variant of an ontology that is in wide use.

Michael

>-----Original Message-----
>From: semantic-web-request@w3.org [mailto:semantic-web-request@w3.org]
>On Behalf Of Antoine Zimmermann
>Sent: Friday, July 16, 2010 1:17 PM
>To: foaf-dev@lists.foaf-project.org; Semantic Web; Linked Data community
>Subject: FOAF DL
>
>Dear all,
>
>
>I know that the compatibility of FOAF with OWL DL has been discussed a
>lot in the past (and still sometimes surfaces again).  However, I'm
>wondering, would it be reasonable to provide a DL version of FOAF in
>complement of the official FOAF ontology?
>More generally, wouldn't it be reasonable to provide alternative
>versions of an ontology?  Think of XHTML: there are three different XML
>Schemas for XHTML [1].  One could imagine alternative versions like FOAF
>(Full), FOAF-DL, FOAF-lite...
>
>Anyway, I did it: I've made a FOAF-DL ontology which modifies the FOAF
>ontology such that (1) it is in OWL 2 DL and (2) it maximally preserves
>inferences of the original FOAF ontology [2].
>
>Interestingly, FOAF-DL is an OWL 2 RL ontology (in a nutshell, OWL 2 RL
>is a subset of OWL 2 DL with low computational complexity and that is
>compatible with rule-based inference engine).
>
>You may notice that there are strange annotation properties for this
>ontology:
>
><owl:Ontology rdf:about="http://purl.org/az/foaf#">
>   ...
>   <yoda:preferredVersion rdf:resource="http://xmlns.com/foaf/0.1/"/>
>   ...
></owl:Ontology>
>
>The Yoda vocabulary [3] is used to relate alternative versions of an
>ontology. Here, it is said that there is a preferred version, which is
>the official FOAF ontology.
>
>Critiques to any of the previous comments are welcome.
>
>
>[1] http://www.w3.org/TR/xhtml1-schema/#schemas
>[2] The FOAF-DL ontology. http://purl.org/az/foaf
>[3] Yoda: A Vocabulary for Linking Alternative Specifications of a
>Vocabulary. http://purl.org/NET/yoda
>
>
>Regards,
>--
>Antoine Zimmermann
>Post-doctoral researcher at:
>Digital Enterprise Research Institute
>National University of Ireland, Galway
>IDA Business Park
>Lower Dangan
>Galway, Ireland
>antoine.zimmermann@deri.org
>http://vmgal34.deri.ie/~antzim/

--
Dipl.-Inform. Michael Schneider
Research Scientist, Information Process Engineering (IPE)
Tel  : +49-721-9654-726
Fax  : +49-721-9654-727
Email: michael.schneider@fzi.de
WWW  : http://www.fzi.de/michael.schneider
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Received on Saturday, 24 July 2010 10:51:22 UTC