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Re: ontology mapping etiquette (was What is the class of a Named Graph?)

From: Pat Hayes <phayes@ihmc.us>
Date: Wed, 24 Feb 2010 01:28:55 -0600
Cc: Richard Cyganiak <richard@cyganiak.de>, Gregory Williams <greg@evilfunhouse.com>, Michael Hausenblas <michael.hausenblas@deri.org>, nathan@webr3.org, Linked Data community <public-lod@w3.org>
Message-Id: <EC3B1C53-00BF-4C6A-8C56-696DC4B26AB7@ihmc.us>
To: Jiří Procházka <ojirio@gmail.com>

On Feb 23, 2010, at 10:47 AM, Jiří Procházka wrote:

> On 02/22/2010 09:44 PM, Richard Cyganiak wrote:
>> On 22 Feb 2010, at 19:36, Jiří Procházka wrote:
>>>>> I wonder if we as a group of people
>>>>> interested in Semantic Web could come up with etiquette for  
>>>>> ontology
>>>>> mapping.
>>>> Interesting topic! My €0.02: If the other vocabulary is likely  
>>>> to be
>>>> - more stable
>>>> - more mature
>>>> - more likely to be widely used
>>>> - more likely to be around for a longer time
>>>> then you should map your terms to it. If not, don't.
>>>> So IMO the rdfg vocabulary should map to the SPARQL Service  
>>>> Description
>>>> vocabulary as soon as it becomes REC, but SPARQL-SD should NOT  
>>>> map to
>>>> rdfg.
>>> Hi Richard, that also seems reasonable to me at first, but when  
>>> thinking
>>> about it more thoroughly, there is value in both ontologies doing  
>>> the
>>> mapping to the other.
>> Yes, if both sides agree, then two-way mappings are great. But this  
>> is
>> only realistic if both vocabularies rate about equally on the  
>> criteria
>> above. As an extreme example, it would be totally unrealistic to  
>> expect
>> the RDFS vocabulary to link back to every vocabulary that has some  
>> sort
>> of label/name property (all of which should be subproperties of
>> rdfs:label).
> Yes, I had in mind especially equivalentClass/Property relations and
> alike where it doesn't scale much, not subproperties.
>> <snip>
>>> Certain mapping statements make sense from PoV of one ontology,  
>>> but not
>>> the other.
>> I don't know what you mean. An example might help. But anyway, if you
>> map to my ontology, but from my POV that mapping doesn't make sense,
>> then I'm certainly not going to map back to yours.
> I mean when the philosophies of the creators of the ontologies aren't
> mutually compatible. I'm unable to come up with some example but just
> let's say that someday we will have religious ontologies...

No need to wait. Already we have for example ontologies which list all  
the elements in the periodic table, others which distinguish isotopes.  
C12 and C14 are both Carbon seen from the non-isotope end, but have to  
be distinguished at the radioactive end. Another example, Cyc (and  
Umbel based on it) say that an element like sodium is a *class* whose  
elements are all *mereological sums* of pure sodium. Dbpedia mentions  
sodium, and they have links, but I bet that most users of Dbpedia  
wouldn't buy into the Cyc ontological craftiness.

Pat Hayes

>> <snip>
>>> If we allow ourselves to go a bit further, I thought it would be  
>>> great
>>> if there was some community developed service which would in  
>>> automated
>>> fashion give advice for improvement and rate user submitted  
>>> (better yet
>>> WoD collected) ontologies judging their quality of design - most
>>> importantly re-usability which basically means how is it aligned to
>>> other similar ontologies. This would be probably very difficult, at
>>> least because of varying opinions on this... I guess database  
>>> community
>>> has something to say about that.
>> I think that's a different issue. When it comes to rating the  
>> “quality”
>> of a vocabulary, then the amount of mappings to other vocabularies  
>> is a
>> very minor factor. First, because other things (especially amount of
>> uptake and strength of the surrounding community) are much more
>> important. Second, because adding the mappings is so easy. No  
>> vocabulary
>> will succeed or fail because of its inclusion or lack of mappings.
> Strength of community and amount of uptake matters really a lot, but
> next thing you are interested in is how an ontology is compatible with
> the rest of your knowledge - how good the mappings are and if it has
> mappings to its "competitors", because the they can have mappings to
> other ontologies you have not (and how they are good).
>> Nevertheless, I agree that we need services that support us in  
>> finding
>> high-quality vocabularies, and that help drive the improvement of
>> existing ones. But it's a complex subject, there are many existing
>> efforts (Watson, Talis Schema Cache, Falcons Concept Search,
>> ontologydesignpatterns.org, and I probably missed a few), and to me  
>> it's
>> not obvious what is the right approach.
>> Perhaps we don't need better ways of finding and creating  
>> vocabularies,
>> but better ways of finding and creating communities around a domain  
>> that
>> can then jointly agree on a vocabulary.
> Great point! I would love to see some development in this area...
>> All the best,
>> Richard
>>> There are more things to talk about regarding this, but this is  
>>> what I
>>> have in mind so far.
>>> Best,
>>> Jiri
>>>> Best,
>>>> Richard
>>>>> Best,
>>>>> Jiri
>>>>>> Hope that helps.
>>>>>> thanks,
>>>>>> .greg
>>>>>> [1] http://www.w3.org/TR/sparql11-service-description/#id41794

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Received on Wednesday, 24 February 2010 07:31:05 UTC

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