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Re: Terminology Question concerning Web Architecture and Linked Data

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Sun, 22 Jul 2007 15:14:56 -0400
Message-Id: <349D315A-41AF-4633-8A03-AAB85830BA4E@gmail.com>
Cc: "SW-forum Web" <semantic-web@w3.org>, "Linking Open Data" <linking-open-data@simile.mit.edu>, "Jonathan A Rees" <jar@mumble.net>, <www-tag@w3.org>
To: Chris Bizer <chris@bizer.de>

Hi Chris,

Thanks for the more detailed information. While I agree with the need  
to be able to have a mechanism for making statements about URIs that  
one doesn't mint, such as http://www.w3.org/People/ Berners-Lee/  
card#i, what I don't follow in your discussion is why such additional  
statements need to be attached to an alias (in the sameAs sense) of  
the original URI. It would seem worth justifying this in the light of  
the associated costs of such aliases

- The lower likelihood of successful "joins" in queries if a) Not all  
"sameAs"s are available to an agent or b) The agent's reasoner isn't  
capable of correctly handling sameAs
- The uncertain semantics of sameAs when taken out of the context of  
the OWL specification.

For instance, why not have e.g. dbpedia only name *resources* which  
are understood as "community statements about" some subject, in which  
statements about tbl would use his designated name for himself?

-Alan


On Jul 20, 2007, at 9:02 AM, Chris Bizer wrote:

> Hi Alan,
>
>> However, I am curious to know what you were asking, so if you do,  
>> I will be appreciative.
>
> My question was aiming more into the direction of how AWWW and OWL  
> terminology plays together.
>
> owl:sameAs if defined as "The built-in OWL property owl:sameAs  
> links an individual to an individual. Such an owl:sameAs statement  
> indicates that two URI references actually refer to the same thing:  
> the individuals have the same "identity" (http://www.w3.org/TR/owl- 
> ref/#sameAs-def)
>
> There was a long discussion and a lot of confusion on the SemWeb  
> list about two weeks ago whether owl:sameAs is the right predicate  
> that should be used to indicate that two URIs refer to the same  
> "thing". With "thing" being a OWL term that does not exist in AWWW  
> terminology.
>
> So, if the anwer to my first question would have been that the  
> different URIs for Tim refer to different resources, there would  
> have been a problem with "refering to the same thing". But as Dan's  
> answer to my first question indicated that the different URIs refer  
> to the same non-information resource, meaning that they are URI  
> aliases, there is no problem and I see the issue as being closed.
>
> Building on this, we argue in section 1.1 of our Linked Data  
> tutorial (http://sites.wiwiss.fu-berlin.de/suhl/bizer/pub/ 
> LinkedDataTutorial/#aliases) that URI aliases provide an important  
> social function to the Web as they are dereferenced to different  
> descriptions of the same non-information resource and thus allow  
> different views and opinions to be expressed.
>
> Which is an interesting conclusion as it conflicts with the AWWW  
> view that URI aliases are harmful.
> See http://www.w3.org/TR/webarch/#uri-aliases
>
> Cheers
>
> Chris
>
>
> --
> Chris Bizer
> Freie Universitšt Berlin
> Phone: +49 30 838 54057
> Mail: chris@bizer.de
> Web: www.bizer.de
>
> ----- Original Message ----- From: "Alan Ruttenberg"  
> <alanruttenberg@gmail.com>
> To: "Chris Bizer" <chris@bizer.de>
> Cc: "Dan Connolly" <connolly@w3.org>; <www-tag@w3.org>; "SW-forum  
> Web" <semantic-web@w3.org>; "Linking Open Data" <linking-open- 
> data@simile.mit.edu>; "Jonathan A Rees" <jar@mumble.net>
> Sent: Friday, July 20, 2007 2:28 PM
> Subject: Re: Terminology Question concerning Web Architecture and  
> Linked Data
>
>
> Hi Chris,
>
> Your assessment is perfectly reasonable. I was thrown off by the
> question you initially asked:
>
>> Question 3: Depending on the answer to question 1, is it correct  
>> to use owl:sameAs [6] to state that http://www.w3.org/People/  
>> Berners-Lee/ card#i and http://dbpedia.org/resource/Tim_Berners- 
>> Lee refer to the same  thing as it is done in Tim's profile.
>
> Given that you didn't intend the sense of "correct" that I thought
> (recall that I was guessing, from context, which sense of correct you
> meant in your question), which sense of "correct" did you mean? Or to
> phrase it another way, if one were to answer the question "no", what
> sort of evidence would you accept to support that answer.
>
> This isn't a matter of philosophy, it's a matter of communication. I
> really don't know what you are asking. Another way to accomplish the
> communication would be to rephrase the question without using the
> word "correct".
>
> I don't mean to suggest you are obligated to clarify this for me.
> However, I am curious to know what you were asking, so if you do, I
> will be appreciative.
>
> -Alan
>
>
>
> On Jul 20, 2007, at 3:55 AM, Chris Bizer wrote:
>
>> Hi Alan,
>>
>> I'm not a philosopher, but I have the feeling that the concept  
>> "correct" in a sence of matching reality does not really apply to  
>> the Semantic Web setting.
>>
>> We are talking about machines that are supposed to process data  
>> from different sources. There is no such thing as "reality" for a  
>> machine. For the machine there is only data! (or knowledge if you  
>> prefer this term)
>>
>> Therefore the question for the machine is: Should it trust a  
>> specific piece of data or not? Or more precisely how can it assess  
>> the quality of the data to a point where it matches the quality  
>> requirements of the user (human).
>>
>> There are lots of different heuristics that a machine can apply to  
>> assess information quality, including content-based, context- 
>> based, rating-based heuristics.
>>
>> For more details than you ever wanted to hear, please refer to my  
>> PhD thesis titeld "Quality-driven Information Filtering in the  
>> Context of Web-based Information System" http://sites.wiwiss.fu-  
>> berlin.de/suhl/bizer/pub/DisertationChrisBizer.pdf
>>
>> Cheers
>>
>> Chris
>>
>> --
>> Chris Bizer
>> Freie Universitšt Berlin
>> +49 30 838 54057
>> chris@bizer.de
>> www.bizer.de
>> ----- Original Message ----- From: "Alan Ruttenberg"  
>> <alanruttenberg@gmail.com>
>> To: "Dan Connolly" <connolly@w3.org>
>> Cc: "Chris Bizer" <chris@bizer.de>; <www-tag@w3.org>; "SW-forum  
>> Web" <semantic-web@w3.org>; "Linking Open Data" <linking-open-  
>> data@simile.mit.edu>; "Jonathan A Rees" <jar@mumble.net>
>> Sent: Friday, July 20, 2007 4:52 AM
>> Subject: Re: Terminology Question concerning Web Architecture and  
>> Linked Data
>>
>>
>>> On Jul 10, 2007, at 1:08 PM, Dan Connolly wrote:
>>>> On Sat, 2007-07-07 at 14:43 +0200, Chris Bizer wrote:
>>>>
>>>>> Question 3: Depending on the answer to question 1, is it   
>>>>> correct to use
>>>>> owl:sameAs [6] to state that http://www.w3.org/People/Berners-  
>>>>> Lee/ card#i and
>>>>> http://dbpedia.org/resource/Tim_Berners-Lee refer to the same  
>>>>> thing as it is
>>>>> done in Tim's profile.
>>>>
>>>> Yes...
>>>>
>>>> That's sort of a circular question. It's correct because Tim   
>>>> says it's correct, and he owns that name.
>>>
>>> That's not the usual sense of "correct". In this context, I  
>>> believe  that the wordnet sense of "correct" that is intended is
>>> "free from error; especially conforming to fact or truth"
>>>
>>> Or Wikipedia: "In everyday use, the correctness of a statement is  
>>> determined by whether or not it matches reality. People can think  
>>> a statement is correct and be wrong."
>>>
>>> If I had a profile that said, in effect, that I was president of  
>>> the United States, then that would be incorrect regardless of  
>>> whether I  owned the name (I am taking the "owned name" that you  
>>> are referring  to to be http://www.w3.org/People/Berners-Lee/  
>>> card#i since that's the  only name in the vicinity that Tim could  
>>> correctly claim to be owned  by him).
>>>
>>> If I'm using the wrong sense of "correct", perhaps you could  
>>> provide  me a definition of "correct" by which I could understand  
>>> your claim.
>>>
>>> Regards,
>>>
>>> -Alan
>>
>
Received on Sunday, 22 July 2007 19:15:25 GMT

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