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Re: http://ld2sd.deri.org/lod-ng-tutorial/

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Mon, 22 Jun 2009 15:08:33 -0400
Message-ID: <4A3FD6B1.2090507@openlinksw.com>
To: martin.hepp@ebusiness-unibw.org
CC: Michael Hausenblas <michael.hausenblas@deri.org>, hepp@ebusiness-unibw.org, Richard Cyganiak <richard@cyganiak.de>, "Hepp, Martin" <mhepp@computer.org>, Hugh Glaser <hg@ecs.soton.ac.uk>, mark.birbeck@webbackplane.com, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "public-lod@w3.org" <public-lod@w3.org>
Martin Hepp (UniBW) wrote:
> Hi Michael:
>
> (moving this to LOD public as suggested)
>
> General note: I am quite unhappy with a general movement in parts of 
> the LOD community to clash with the OWL world even when that is 
> absolutely unnecessary. It is just a bad engineering practice to break 
> with existing standards unless you can justify the side-effects. And 
> this stubborn "i don't care what the OWL specs says" pattern is silly, 
> in particular if the real motivation of many proponents of this 
> approach is that they don't want or cannot read the OWL specs.
>
> As for owl:imports:
>
> When importing an ontology by owl:imports, you commit to the whole 
> formal account of that ontology. If you just include an element from 
> that ontology by using it and hope that dereferencing will get the 
> relevant formal account in your model, you expose your model to 
> randomness - you don't know what subset of the formal account you will 
> get served. Ontology modularization is a pretty difficult task, and 
> people use various heuristics for deciding what to put in the subset 
> being served for an element. There is no guarantee that the fragment 
> you get contains everything that you need.
>
> On the other hand - what is your pain with  using RDFa in a way so 
> that the extracted RDF model is equivalent to the model from an 
> RDF/XML or N3 serialization? Why this absolutely arbitrary "we LOD 
> guys don't like owl:import ( we don't like OWL anyway, you know?), so 
> we simply omit it" behavior?
>
> It is just silly to break with established standards just for saving 1 
> - 2 triples.
All,

There is a simple rule of thumb re. technology that ultimately works 
long term (i.e. scales when edge cases surface) and its called: 
Deceptively Simple. We have to understand that real tech. that makes any 
significant difference over the long term always has a strong 
"deceptively simple" component to it e.g., HTTP as a prime example.

"Simply Simple" does not work, it doesn't scale due inherent autism re. 
edge cases. Popularity != work if you end up down a technology 
cul-de-sac, ultimately!

Note: Web 2.0 is the land of "Simply Simple" and in due cause we will 
all see that its sole purpose has been evolving the Web to a point where 
the case for Linked Data and the essential vision of the Semantic Web 
Project are much easier to comprehend and appreciate.

Personally, I will never understand the anti OWL sentiment that appears 
to exist in some LOD quarters; especially as OWL based reasoning 
combined with Linked instance Data is where the real magic resides.


Courtesy of the GoodRelations Ontology, we're now able to sharpen the 
Linked Data value prop. down to a slogan that reads:
Describe your wants/needs or products/services clearly, then simply 
leave the Web to do the REST.

The most significant takeaway from Semtech2009 was the fact that Yahoo! 
and Google already grok the implications of the statement above, via the 
lenses of RDFa as a mechanism for expressing and exposing GoodRelations 
based Linked instance Data.

OWL is important, and lets collectively work to improve its 
appreciation. What's good for the ABox is also good for the TBox re. our 
collective efforts :-)

Kingsley
>
> Best
> Martin
>
> Michael Hausenblas wrote:
>> Martin, 
>>
>> As an aside: I think I proposed already once to not have this discussion in
>> a private circle of 'randomly' selected people but rather in the appropriate
>> lists (rdfa public or public-lod). However, if you prefer to continue here,
>> we continue here, FWIW.
>>
>>   
>>>> In my opinion the owl:imports
>>>> stems from a time where people confused publishing on the Semantic Web with
>>>> firing up Protege and clicking around like wild. So, concluding, for me it
>>>> is not obvious to use owl:imports and I don't see *any* benefit from using
>>>> it. Not in RDF/XML and also not in RDFa ;)
>>>>       
>>> you know that i sometimes appreciate your opinion ;-),
>>>     
>>
>> Yeah, same here :D
>>
>>   
>>> ... but i think it is
>>> pretty questionable to break with well-defined standards specifications
>>> for just a matter of gut feeling and personal preference.
>>>     
>>
>> Ok, let me rephrase this. You, or whoever publishes RDFa can of course do
>> whatever she likes. Wanna use owl:imports? Fine. Don't wanna use it. Ok!
>>
>> The point I was trying to make (not very successfully, though): from a
>> linked data perspective (and basically this is what Richard and I try to
>> achieve here; offering good practices for linked data *in* RDFa) the usage
>> of owl:imports is, how to put it, not encouraged.
>>
>> So far I have not heard any convincing argument from you why one should use
>> it, but I'm happy and open to learn.
>>
>> Cheers,
>>       Michael
>>
>>   
>
> -- 
> --------------------------------------------------------------
> 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
>
>
>
>   


-- 


Regards,

Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Monday, 22 June 2009 19:09:35 UTC

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