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Re: comments on RDF mapping

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Tue, 30 Oct 2007 14:17:27 -0400 (EDT)
Message-Id: <20071030.141727.164726030.pfps@research.bell-labs.com>
To: vit.novacek@deri.org
Cc: public-owl-wg@w3.org, rector@cs.man.ac.uk

From: "Novacek, Vit" <vit.novacek@deri.org>
Subject: RE: comments on RDF mapping
Date: Tue, 30 Oct 2007 18:10:27 -0000

> > >   Anyway, this is a long way to say that I second the idea that we  
> > > might want to revisit annotations w/respect to allowing a "minimal"  
> > > semantics to them - so it woudln't break DL implementations, but  
> > > would allow this feature to be more widely used by tools.
> > 
> > +1
> 
> > As you are agreeing, presumably you have some example tools and uses.
> > Could you share them with the WG?
> 
> I'm sorry, I realised I should have given a more elaborated explanation 
> already when reading the e-mail [1]...
> 
> Maybe I do not have exactly the same "conceptualisation" of the "minimal 
> semantics" expression used in the original e-mail - however, in the following
> I'll try to give initial elaboration of the reasons why I supported this, 
> together with a sketch of applications that could make use of this "minimal
> semantics" of annotations. Note that these views are very roughly outlined
> at this stage and open to any discussion and comments - I'm also really 
> open to any remarks pointing me to issues and materials that could help me 
> with my concerns, since I'm quite new to this initiative and I'm very well 
> aware of that.
> 
> First of all, I do not object against the fact that annotations should not 
> interfere with the DL-based inference in OWL1.1 - I think this should
> be separated, indeed. So, "minimal annotation semantics" != logical 
> (model-theoretic) semantics of OWL1.1 recommendation in my view, therefore, 
> no need for reasoners to try to cope with this "mess". However, I think it 
> could be useful to come with a kind of very general granularisation of 
> annotations in OWL1.1 - i.e., to propose and model basic annotation "types",
> possibly extensible by users. RDFS constructs like rdfs:label can obviously 
> be re-used and sub-typed in this annotation hierarchy proposal. I can imagine 
> the following example applications from the top of my head:
> 
> i) Annotations can be part of the axioms, according to the document [2], 
> Section 3. This would allow to connect for instance versioning-related
> information (time-stamp, information on version since which this 
> axiom has been introduced into the ontology, etc.) not only to the ontology as 
> such, but also to particular axioms. Of course, this could be done even now
> using rdfs:label or rdfs:comment, but these properties can be used for many
> other purposes, too. So, maybe it could be useful to have a common 
> versioning-related annotation types in order to let applications make use
> of these features in uniformly defined (i.e., standard) way. I cannot 
> really estimate practical impact of this, however, it may not be a complete
> non-sense in my opinion...

Ok, but then why not just have an annotation properties like
ex:time-stamp and ex:version-introducted?  

> ii) I have certain informal indications among the members of our institute
> that a standardised way of uncertainty representation (in OWL) would be a
> useful feature for their applications. According to the list referenced in [3], 
> these features are de facto considered to be a part of rather far future 
> (OWL 2.0), concerning their full incorporation into OWL (presumably into its
> model-theoretic semantics). However, having a special annotation type for 
> expressing uncertainty (in a uniform way, not by arbitrary use of the
> generic annotation properties, again) would allow for this already now.
> The DL reasoners can safely omit such information in annotations, but 
> applications that would like to make use of uncertainty measures 
> associated with particular axioms could actually do it then, utilising a common
> way of uncertainty representation in OWL1.1, using a dedicated type of 
> annotations. No matter whether they'd use the uncertainty measures just for 
> ranking axioms in user interfaces, or for fuzzy-DL reasoning [4], or for 
> whatever other purposes. 

Again, one or more OWL 1.1 annotations seem to be adequate here.

> Hope I made myself clear enough - feel free to ask for any further 
> clarification if needed...
> 
> Cheers,
> Vit
> 
> [1] http://lists.w3.org/Archives/Public/public-owl-wg/2007Oct/0368.html
> [2] http://www.webont.org/owl/1.1/owl_specification.html
> [3] http://lists.w3.org/Archives/Public/public-owl-wg/2007Oct/0347.html
> [4] http://owled2007.iut-velizy.uvsq.fr/PapersPDF/submission_12.pdf

peter
Received on Tuesday, 30 October 2007 18:28:52 GMT

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