Re: Conceptual Modeling and the Web of Linked Data - was Re: Recipe for Shops: Showing up in Yahoo

On Jul 23, 2009, at 4:10 AM, Martin Hepp (UniBW) wrote:

> Hi Benjamin
> Benjamin Nowack wrote:
>> On 22.07.2009 14:52:05, Hugh Glaser wrote:
>>>> Benjamin Nowack wrote:
>>>>> Interesting. I guess this is another argument/example pro Hugh
>>>>> Glaser's idea of simply conflating resource IDs for the sake of
>>>>> "deployability". The example types <#business> as Vcard, Business
>>>>> and also as BusinessEntity which would usually be considered wrong
>>>>> RDF, but, as argued before, is more intuitive for HTML authors,
>>>>> especially if they found their way to the SemWeb through pragmatic
>>>>> solutions like microformats. We should really give this contextual
>>>>> semantics idea another thought.
>>>> Actually, I disagree completely
>>> Actually, not sure I agree either :-)
>> heh, neither am I ;)
>> But if even RDFers get the semantics wrong or simply interpret a
>> non-exact schema individually for their personal use case, it just
>> shows that data consumers and app builders will have to go beyond
>> strict RDF principles.
> Actually, for me it confirms that
> 1. there can be differences between the formal semantics and the  
> social semantics of elements in conceptual structures.
> 2. it is practically impossible to define the intended meaning of  
> conceptual elements solely by formal means.

Seems to me this is too pessimistic. The lesson I would draw is that  
the formal semantic analysis needs to become more aware of, and able  
to properly take account of, these social aspects of meaning. And  
while this is a challenge, I don't think that it is 'practically  
impossible'. However, it is longer term than is needed for currently  
deployability, I will concede :-)

> But we should avoid differences between the social semantics and the  
> formal semantics as much as possible, instead of celebrating
> the social re-definition of formally defined conceptual elements, as  
> it happens in the case of owl:sameAs or the use of owl:imports.
> Some tweaks may be necessary to make the Web of Linked Data fly. A  
> too "tweakish" attitude, however, will just create another
> tower of bable.


> The main challenge in building good vocabularies is the conflict  
> between two extremes:
> 1. Very fine-grained conceptual structures (many classes, many  
> elements) are more burdensome to fill with data, but empower a  
> better mechanized reuse of the data.
> 2. Very coarse conceptual structures are easy to populate, but  
> require a lot of human intelligence or machine guesswork when  
> processing or reusing the data.
> See also
> In a broader sense and based on about ten years of conceptual  
> modeling for exchanging information, the key task when building  
> useful vocabularies / schemas / ontologies for the Web of Linked  
> Data is
> to find categories of existence (classes, properties, ...) that
> 1. Are easy to populate from existing data sources (popular database  
> schemas etc.)
> 2. Are sufficiently subtle to allow machine-processing of the data  
> (e.g. separating values from units of measurement)

And, I would add, are such that their subtleties can be quickly and  
easily understood by the people who will be required to adopt them,  
once they are properly explained.

> 3. Are valid across multiple individuals (e.g. that class membership  
> is agreed by many users)
> 4. Are valid across time (e.g. that class membership is relatively  
> stable over time - "MostPopularSinger" is a class with very dynamic  
> class membership)
> 5. Are valid across multiple contexts (e.g. that class membership  
> remains valid if the data is used in novel contexts)

Often, however, validity is in the eye of the beholder. Many of our  
knowledge interoperability problems arise because people have learned  
to reject certain kinds of classifications as mistaken or  
inappropriate, when in fact they are no *formal* reasons why they  
cannot be used. The formalisms are often less restrictive than the  
prejudices imposed upon them by their human users. One sees this very  
often when people object to 'mixing data with metadata' , for example,  
or to classes which violate perceived 'layers' of abstraction.

Pat Hayes

> Three slides on this topic:
> Martin
> -- 
> --------------------------------------------------------------
> martin hepp
> e-business & web science research group
> universitaet der bundeswehr muenchen
> e-mail:
> phone:   +49-(0)89-6004-4217
> fax:     +49-(0)89-6004-4620
> www: (group)
> (personal)
> skype:   mfhepp
> twitter: mfhepp
> Check out the GoodRelations vocabulary for E-Commerce on the Web of  
> Data!
> = 
> = 
> ======================================================================
> Webcast:
> Talk at the Semantic Technology Conference 2009:
> "Semantic Web-based E-Commerce: The GoodRelations Ontology"
> Tool for registering your business:
> Overview article on Semantic Universe:
> Project page and resources for developers:
> Tutorial materials:
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> Hands-on Introduction to the GoodRelations Ontology, RDFa, and  
> Yahoo! SearchMonkey
> <martin_hepp.vcf>

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Received on Friday, 24 July 2009 18:47:38 UTC