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

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.

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 http://www.heppnetz.de/files/iswc-lightning-talk-hepp3.png

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)
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)

Three slides on this topic:

http://www.heppnetz.de/files/eswc01.pdf
http://www.heppnetz.de/files/iswc-lightning-talk-hepp2.png


Martin

-- 
--------------------------------------------------------------
martin hepp
e-business & web science research group
universitaet der bundeswehr muenchen

e-mail:  mhepp@computer.org
phone:   +49-(0)89-6004-4217
fax:     +49-(0)89-6004-4620
www:     http://www.unibw.de/ebusiness/ (group)
         http://www.heppnetz.de/ (personal)
skype:   mfhepp 
twitter: mfhepp

Check out the GoodRelations vocabulary for E-Commerce on the Web of Data!
========================================================================

Webcast:
http://www.heppnetz.de/projects/goodrelations/webcast/

Talk at the Semantic Technology Conference 2009: 
"Semantic Web-based E-Commerce: The GoodRelations Ontology"
http://tinyurl.com/semtech-hepp

Tool for registering your business:
http://www.ebusiness-unibw.org/tools/goodrelations-annotator/

Overview article on Semantic Universe:
http://tinyurl.com/goodrelations-universe

Project page and resources for developers:
http://purl.org/goodrelations/

Tutorial materials:
Tutorial at ESWC 2009: The Web of Data for E-Commerce in One Day: A Hands-on Introduction to the GoodRelations Ontology, RDFa, and Yahoo! SearchMonkey

http://www.ebusiness-unibw.org/wiki/GoodRelations_Tutorial_ESWC2009