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Re: Are there any plans to develop an OWL version of QUDT?

From: Ivan Herman <ivan@w3.org>
Date: Thu, 8 May 2014 10:17:22 +0200
Cc: Holger Knublauch <holger@topquadrant.com>, W3C Web Schemas Task Force <public-vocabs@w3.org>, Ralph Hodgson <rhodgson@topquadrant.com>
Message-Id: <82B9EE93-653D-4E04-9ED3-AD01B6062565@w3.org>
To: Simon Spero <sesuncedu@GMAIL.COM>
Simon,

On 08 May 2014, at 03:41 , Simon Spero <sesuncedu@GMAIL.COM> wrote:

> On May 6, 2014, at 8:19 PM, Holger Knublauch <holger@topquadrant.com> wrote:
> 
>> +1
>> 
>> OWL DL is IMHO an academic niche language while most real-world projects that I have seen don't need or want its limitations. I also find it alarming if people argue that we should not use RDF features only because their favorite ontology editor and API cannot handle RDF. Being limited to OWL DL was a design decision that those tools made, while other tools have no problems with RDF.
>> 
>> Holger
> 
> You raise some good points;  as I have often stated (pace pfps) , I consider Description Logics to be rather weak tea, and whilst they are very well suited to a certain class of problem, I greatly prefer non-montonic, higher order systems for general KR problems. 
> 
> However, some of the points you make require some caveats.   
> 
> Firstly:  
>    If a problem falls within the class of problems that OWL 2 DL can handle, it is good to stay within the constraints of DL.  Going to OWL Full should be made on a carefully considered basis of costs vs. benefits.  
> 
> Secondly: 
>       The mapping from OWL to RDF is explicitly only defined for OWL-DL.  It is not possible always possible to parse an OWL-2 ontology that does not follow some of the DL restrictions.  One can make a best effort, but the mapping from OWL 2 Full to RDF is a one way trip, as the OWL to RDF mapping specifications makes clear in the first paragraph of the first section. 

To be honest, I am not sure what you mean or, more exactly, where you perceive a problem. 

http://www.w3.org/TR/owl2-mapping-to-rdf/#Mapping_from_the_Structural_Specification_to_RDF_Graphs

defines the mapping of *any* OWL to RDF, regardless of the semantics used. It is true that

http://www.w3.org/TR/owl2-mapping-to-rdf/#Mapping_from_RDF_Graphs_to_the_Structural_Specification

defines the _inverse_ mapping from an RDF graph onto the OWL 2 functional specification has some restrictions but I would not consider it as a problem for the discussion at hand: the OWL 2 Full semantics

http://www.w3.org/TR/owl2-rdf-based-semantics/

defines the necessary rules in terms of RDF graphs only.

Maybe you meant: 'The mapping from RDF to OWL is explicitly only defined for OWL-DL'? Which is correct but, in fact, mapping to OWL-Full is not really useful because OWL-Full is defined in RDF only...

Ivan

> 
> Thirdly:  
>         The vocabularies being discussed were inconsistent at every level of the RDF, RDFS, and OWL chain, and contained basic type errors. I do not know what tools were used to create them, but whatever tool it was could not do basic consistency checking.   
> 
> Fourthly:  
>      If a vocabulary or tool claims to comply with  standards/(W3C recommendations), it is very important that the vocabulary/tool should comply with those standards. If a vocabulary tool is intended to follow a standard, but is in fact non compliant, then it is a major bug.  
> 
> As Ralph said, he considers the problems I reported to be potentially serious issues, and will be looking in to them in detail.
> 
> Simon


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Ivan Herman, W3C 
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Received on Thursday, 8 May 2014 08:17:55 UTC

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