Re: Defining subsets of existing OWL / RDF-S vocabularies in another vocabulary?

Dear all:
Summarizing the discussion :-)
My main point was whether it is fine to locally specify the semantics of 
a conceptual element that is in someone else's domain space in my own 
ontology, assumed that

a) I am specifying it in exactly the same way as the owner of that URI 
space does (no differences in the formal and in the intended semantics 
of the element) and
b) I am able to solve all the issues in extracting the full 
specification for a single element from a larger vocabulary / ontology, 
which can be an issue in more expressive ontology languages, namely OWL DL.

There seems to be consensus that, given that a) and b) are mastered, 
there are no objections against it from a Web architecture perspective.


Thanks for all your valuable comments!

Best

Martin
---------------------------------------
http://www.heppnetz.de

Richard Cyganiak wrote:
> Alan,
> 
> On 29 Sep 2007, at 23:33, Alan Ruttenberg wrote:
>>> But if you exchange data with the rest of the world, then you'll have 
>>> to keep in mind that some agents are web-aware, and will get their 
>>> definition of foaf:name from http://xmlns.com/foaf/0.1/name, and not 
>>> from your copy, regardless of whatever owl:imports you may have 
>>> declared.
>>
>> An agent that is "web-aware" in such a way as to ignore owl:imports, 
>> and retrieve definitions of terms in an OWL ontology from the web 
>> would be in variance with the OWL specification. If something is to be 
>> fixed, it is the web agent. To build anything to conform to a buggy 
>> system is a corrupting influence on the web, vis browser hassles with 
>> ensuring compatibility with IE, bugs and all.
> 
> OWL is layered on top of RDF and RDFS. There are several agents that do 
> not understand OWL, but employ semantic extensions such as 
> follow-your-nose and other breadcrumb protocols. These are popular modes 
> of operation in the FOAF and LOD communities, and I wouldn't consider 
> them “buggy systems”.
> 
> If Martin intends to publish his data on the Semantic Web, then I think 
> it is good advice to consider the behaviour of such clients. As I said 
> before, if he just builds a silo and doesn't intend to publish his data, 
> then he does not need to consider this.
> 
>>> If you really want to make sure that all agents encountering your 
>>> data work off the same vocabulary definitions, then you should 
>>> probably duplicate the relevant terms in your own namespace, creating 
>>> hepp:name and hepp:knows and so on, and declare them 
>>> owl:equivalentProperty to the original terms.
>>
>> If you really want to make sure that all agents encountering your data 
>> work off the same vocabulary definitions, then you need to follow the 
>> specification. If we follow the specification, then web agents 
>> designers will appreciate  that it is worth learning what the 
>> specification says and we will all be better off. If not, we will 
>> compound the problem by doing what we think some undocumented web 
>> agent wants, because this will undoubtedly violate the undocumented 
>> assumptions of some other web agent not following the spec.
> 
> Care to point me to *any* Semantic Web agent that does not employ some 
> sort of semantic extension of the vanilla specs in order to get its job 
> done?
> 
>> That said, it has been my practice to define, within my owl ontology, 
>> select terms from other ontologies, when I make an assessment that I 
>> am not changing the intended meaning of the term, and when importing 
>> the full ontology would have undesirable effects - for instance making 
>> my ontology OWL-Full, or when the source ontology has bugs that 
>> violate their own english definitions, or then the source ontology is 
>> too large to import for practical reasons. I'm not suggesting that 
>> this is the best idea - time will tell.
>>
>> YMMV for RDFS, where the means of specifying how definitions are to be 
>> retrieved are, at best, loosely specified.
> 
> Martin referred to FOAF and DC specifically, both of which are designed 
> to work with RDFS-only agents as well as OWL-capable agents.
> 
> Richard
> 
> 
> 
>>
>> -Alan
>>
>>>
>>> Best,
>>> Richard
>>>
>>>
>>>>
>>>> If that was okay, it would make it easier to prepare pre-composed 
>>>> blends of relevant ontologies that can be directly used for 
>>>> form-based instance data creation.
>>>>
>>>> However, I fear that defining an element that is residing in someone 
>>>> else's URI space is not okay, since I (e.g. http://www.heppnetz.de) 
>>>> have no authority of defining the semantics of an element that is 
>>>> within
>>>> |http://xmlns.com/foaf/0.1/, even if I what I am saying is 
>>>> consistent with the authoritative definition of the given vocabulary 
>>>> element. |
>>>> ||
>>>> ||I am assuming that I duplicate the very same specification of the 
>>>> element, i.e., I would assure that my definition just replicates a 
>>>> subset of the official vocabulary. I also abstract from semantic 
>>>> dependencies, i.e., whether it is possible to specify a consistent 
>>>> subset of a given vocabulary (this may not be trivial for an 
>>>> expressive DL ontology, but should be feasible for lightweight RDF-S 
>>>> or OWL vocabularies). Also, the legal point of view (whether I am 
>>>> allowed to replicate an existing specification) is less relevant for 
>>>> me at the moment. I just want to know whether this is an acceptable 
>>>> practice from a Web Architecture perspective.
>>>>
>>>> Any feedback would be very much appreciated!
>>>>
>>>> Best
>>>>
>>>> Martin
>>>> -----------------------------------------------------
>>>>
>>>> martin hepp
>>>> e-mail: martin.hepp@deri.at
>>>> web:    http://www.heppnetz.de
>>>> skype:  mfhepp
>>>> office: +43 512 507 6465
>>>>
>>>> Check eClassOWL, the first real-world e-business ontology
>>>> for products and services in OWL at
>>>> http://www.heppnetz.de/eclassOWL
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
> 
>

Received on Friday, 2 November 2007 22:18:40 UTC