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Fw: Why do you want to do that?

From: Richard H. McCullough <rhm@pioneerca.com>
Date: Fri, 8 Aug 2008 09:50:08 -0700
Message-ID: <45A3155829BA4E08B0C19C9E48AB3E67@rhm8200>
To: "Semantic Web at W3C" <semantic-web@w3.org>

I forgot to Cc: semantic web at w3c.

Dick McCullough
Ayn Rand do speak od mKR done;
mKE do enhance od Real Intelligence done;
knowledge := man do identify od existent done;
knowledge haspart proposition list;
http://mKRmKE.org/

----- Original Message ----- 
From: "Richard H. McCullough" <rhm@pioneerca.com>
To: "Sören Auer" <auer@informatik.uni-leipzig.de>
Sent: Friday, August 08, 2008 9:45 AM
Subject: Re: Why do you want to do that?


> Hi Soren
> Thanks for your response.
> 2. In a car ontology, I think
>    /Tesla Roadster/  type  /Cars/;
> is an error.  It should be
>    /Tesla Roadster/  subClassOf  /Cars/;
> That's my 2ct.
> A good weekend to you!
>
> Dick McCullough
> Ayn Rand do speak od mKR done;
> mKE do enhance od Real Intelligence done;
> knowledge := man do identify od existent done;
> knowledge haspart proposition list;
> http://mKRmKE.org/
>
> ----- Original Message ----- 
> From: "Sören Auer" <auer@informatik.uni-leipzig.de>
> To: "Richard H. McCullough" <rhm@pioneerca.com>
> Cc: "Semantic Web at W3C" <semantic-web@w3.org>; "KR-language" 
> <KR-language@YahooGroups.com>; "Adam Pease" <adampease@earthlink.net>; 
> "Pat Hayes" <phayes@ihmc.us>
> Sent: Friday, August 08, 2008 9:28 AM
> Subject: Re: Why do you want to do that?
>
>
>> Richard H. McCullough wrote:
>>> Over the last six years, I have suggested a number of
>>> "improvements" to the RDF language.  Not one of
>>> my suggestions was adopted.  Apparently,
>>> RDF is fine just the way is, thank you!
>>>
>>> I would now like to turn the tables, and ask
>>> why do you want to do that?
>>
>> Richard, I have the impression you misunderstand the intentions of RDF a 
>> little. I'm not involved in RDF standardization, but as I understand RDF 
>> it is just a very simple datamodel (the triple datamodel) with various 
>> serializations. In this datamodel you can encode other more richer 
>> knowledge representation formalisms such as RDF-Schema, the various OWL 
>> dialects, but also completely different information such as rules, 
>> relational data, lenses for visualisation, low level vocabularies (SIOC, 
>> FOAF, DC etc.) and so on ...
>>
>>> I'll start with two features of RDF which seem to be popular.
>>>
>>> 1. X  subClassOf  X;
>>> A neat mathematical property, right?
>>> But if you do the inferences, what it means is
>>>    X  sameAs  X;
>>> We already knew that.
>>> Why do you want to do that?
>>
>> The properties you mention are not defined in RDF: subClassOf is an 
>> RDF-Schema property and sameAs is defined in OWL. Furthermore, sameAs can 
>> not only be used between Classes, but between arbitrary resources. Also 
>> from a more theoretic standpoint both are different: subClassOf just 
>> talks about the class extends, i.e. the instances of the two classes, 
>> while sameAs is related to properties attached to each resource being 
>> exactly the same (i.e. both identifiers being synonyms).
>> You are right in this special case there is some redundancy, but you will 
>> find a lot more in most knowledge bases and I think being minimal was not 
>> a design goal of RDFS or OWL. If you really don't like redundancies you 
>> can simply remove derivable statements from your KB.
>>
>>> 2. X  type  Y;  X  subClassOf  Z;
>>> Another neat property: X is an individual and a class.
>>> Now I can ... What?  I don't know.
>>> Why do you want to do that?
>>
>> Why not? Of course in most local KBs this does not make much sense, and 
>> in OWL-DL for example this would not be allowed. On the other hand, the 
>> Semantic Web knowledge representation stack is meant to be used on the 
>> Web integrating knowledge and information from different sources (and 
>> viewpoints). What appears to be an instance for one user might be a class 
>> for another one. Think for example of /Tesla Roadster/ being an instance 
>> a class /Cars/ in a car ontology, but from the viewpoint of the 
>> manufacturer /Tesla Roadster/ is a class with the instances /Sergei's 
>> Tesla/, /Larry's Tesla/, /Elon's Tesla/. ;-)
>>
>> Just my 2ct, have a nice weekend
>>
>> Sören
>>
>> -- 
>>
>> --------------------------------------------------------------
>> Sören Auer, AKSW/Computer Science Dept., University of Leipzig
>> http://www.informatik.uni-leipzig.de/~auer,  Skype: soerenauer
>>
>>
> 
Received on Friday, 8 August 2008 16:50:54 GMT

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