- From: Haijie.Peng <haijie.peng@gmail.com>
- Date: Sat, 03 Jul 2010 12:12:38 +0800
- To: Kingsley Idehen <kidehen@openlinksw.com>
- CC: Pat Hayes <phayes@ihmc.us>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
On 2010/7/1 22:42, Kingsley Idehen wrote:
> Pat Hayes wrote:
>>
>> On Jun 30, 2010, at 3:49 PM, Kingsley Idehen wrote:
>>
>>> Pat Hayes wrote:
>>>>
>>>> On Jun 30, 2010, at 1:30 PM, Kingsley Idehen wrote:
>>>>
>>>>> Nathan wrote:
>>>>>> Pat Hayes wrote:
>>>>>>> On Jun 30, 2010, at 6:45 AM, Toby Inkster wrote:
>>>>>>>> On Wed, 30 Jun 2010 10:54:20 +0100
>>>>>>>> Dan Brickley <danbri@danbri.org> wrote:
>>>>>>>>> That said, i'm sure sameAs and differentIndividual (or however
>>>>>>>>> it is
>>>>>>>>> called) claims could probably make a mess, if added or removed...
>>>>>>>>
>>>>>>>> You can create some pretty awesome messes even without OWL:
>>>>>>>>
>>>>>>>> # An rdf:List that loops around...
>>>>>>>>
>>>>>>>> <#mylist> a rdf:List ;
>>>>>>>> rdf:first <#Alice> ;
>>>>>>>> rdf:next <#mylist> .
>>>>>>>>
>>>>>>>> # A looping, branching mess...
>>>>>>>>
>>>>>>>> <#anotherlist> a rdf:List ;
>>>>>>>> rdf:first <#anotherlist> ;
>>>>>>>> rdf:next <#anotherlist> .
>>>>>>>>
>>>>>>>
>>>>>>> They might be messy, but they are *possible* structures using
>>>>>>> pointers, which is what the RDF vocabulary describes. Its just
>>>>>>> about impossible to guarantee that messes can't happen when all
>>>>>>> you are doing is describing structures in an open-world setting.
>>>>>>> But I think the cure is to stop thinking that possible-messes
>>>>>>> are a problem to be solved. So, there is dung in the road. Walk
>>>>>>> round it.
>>>>>>>
>>>>>>
>>>>>> Could we also apply that to the 'subjects as literals' general
>>>>>> discussion that's going on then?
>>>>>>
>>>>>> For example I've heard people saying that it encourages bad
>>>>>> 'linked data' practise by using examples like { 'London' a
>>>>>> x:Place } - whereas I'd immediately counter with { x:London a
>>>>>> 'Place' }.
>>>>>>
>>>>>> Surely all of the subjects as literals arguments can be countered
>>>>>> with 'walk round it', and further good practise could be aided by
>>>>>> a few simple notes on best practise for linked data etc.
>>>>>
>>>>> IMHO an emphatic NO.
>>>>>
>>>>> RDF is about constructing structured descriptions where "Subjects"
>>>>> have Identifiers in the form of Name References (which may or many
>>>>> resolve to Structured Representations of Referents carried or
>>>>> borne by Descriptor Docs/Resources). An "Identifier" != Literal.
>>>>
>>>> What ARE you talking about? You sound like someone reciting doctrine.
>>>>
>>>> Literals in RDF are just as much 'identifiers' or 'names' as URIs
>>>> are. They identify their value, most clearly and emphatically. They
>>>> denote in exactly the same way that URIs denote. "23"^^xsd:number
>>>> is about as good an identification of the number twenty-three as
>>>> you are ever likely to get in any notational system since ancient
>>>> Babylonia.
>>>
>>> Yes, but ancient Bablyonia != World Wide Web of Structured Linked
>>> Data, slightly different mediums with some shared characteristics :-)
>>>
>>> The World Wide Web is becoming a Distributed DBMS (in my eyes).
>>> Thus, unambiguous naming matters.
>>
>> A topic for a longer discussion; but irrelevant here, since typed
>> literals are as unambiguous as a name can possibly get.
>>
>>>
>>> Literal Subjects aren't a "show stopper" per se. (esp. for local RDF
>>> data). My gripe simply boils down to the nuisance factor introduced
>>> by data object name ambiguity in a distributed data object oriented
>>> realm such as the emerging Web of Linked Data.
>>>
>>> What does ""23"^^xsd:number " mean to anyone in a global data space?
>>
>> It means the number twenty-three, everywhere and for all time,
>> because this meaning can be computed from the very syntactic form of
>> the name. How unambiguous can something get?
>
> Pat,
>
> Re. RDF's triples, What is a Subject? What is an Object?.
>
> If they are the same thing, why on earth do we use Names (with
> implications) to describe the slots in an RDF triple?
>
> I've only once seen the RDF triple referred to as O-R-O (by @danbri)
> i.e., Object-Relation-Object.
>
> In addition, I don't see Information and Data as being the same thing.
> Information (as I know it) is about Data + Context. Raw Data (as I
> know it) is about: a unit of observation and deemed worthy of
> description by its observer. You have to give Names to subject of a
> description. "23"^^xsd:number isn't a Name.
>
> **
> I guess my own subtle mistake (re. this thread) is deeming Identifiers
> and Names to be equivalent , when they aren't :-) Of course, one can
> use an Identifier as a Name, but that doesn't make them equivalent.
> **
>
>
> One clear point of divergence here is that I am focused on the Web as
> Dist. DBMS that leverages 3-tuples + HTTP URIs in the S, P, and
> optionally O slot (aka. HTTP based Linked Data).
>
> To conclude:
>
> Name != Identifier.
We can also question the role of URI. Because the location of resource
pointed by URI and the content of URI are orthogonal. A location is
interpreted by a set of locating operations, the locating result is
only GUIDED, not CONTROLLED, by the content of URI. To realize this is
very important!
regards
Peng
>
> I believe Subject == Name (an Identifier based Name) re. RDF triples
> otherwise the triple should be described as: O-R-O or O-P-O.
>
> I believe an S-P-O triple is a piece of information (Data Object has a
> Name and at least one Attribute=Value pair).
>
> What I desscribe actually has zilch to do with RDF as I am inclined to
> believe you see RDF :-) Thus, in a way, the literal-subject debate may
> simply help everyone understand and accept that RDF != Linked Data.
> Thus, providing additional proof that RDF isn't mandatory or even
> required re. delivery of HTTP based Linked Data.
>
> RDF based Linked Data != RDF. They are different things, clearly. We
> can't have it both ways (** Pat: not for you, that's for those that
> deem RDF and Linked Data inextricably linked **).
>
>
> BTW - I still have no idea if RDF and RDF/XML are really distinct.
> HTML and N3 built the Web of Linked Data, but N3 remains a 2nd or 3rd
> class citizen whenever we talk about the pragmatic aspects of what
> continues to be inappropriately labeled as an RDF virtue i.e. Linked
> Data.
>
> Danbri:
>
> I agree with the essence of your earlier post!
>
>
> Kingsley
>
>
>>
>> Pat
>>
>>
>>> I know the meaning of:
>>> <http://km.aifb.kit.edu/projects/numbers/web/n23#this>, based on the
>>> resource I deref at: <http://km.aifb.kit.edu/projects/numbers/web/n23>
>>>
>>>
>>>
>>> Kingsley
>>>
>>>
>>>>
>>>> Pat Hayes
>>>>
>>>>>
>>>>> If you are in a situation where you can't or don't want to mint an
>>>>> HTTP based Name, simply use a URN, it does the job.
>>>>>
>>>>>
>>>>>>
>>>>>> Best,
>>>>>>
>>>>>> Nathan
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> Regards,
>>>>>
>>>>> Kingsley Idehen President & CEO OpenLink Software
>>>>> Web: http://www.openlinksw.com
>>>>> Weblog: http://www.openlinksw.com/blog/~kidehen
>>>>> Twitter/Identi.ca: kidehen
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>> ------------------------------------------------------------
>>>> IHMC (850)434 8903 or (650)494
>>>> 3973
>>>> 40 South Alcaniz St. (850)202 4416 office
>>>> Pensacola (850)202 4440 fax
>>>> FL 32502 (850)291 0667 mobile
>>>> phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>>
>>> Regards,
>>>
>>> Kingsley Idehen President & CEO OpenLink Software Web:
>>> http://www.openlinksw.com
>>> Weblog: http://www.openlinksw.com/blog/~kidehen
>>> Twitter/Identi.ca: kidehen
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> ------------------------------------------------------------
>> IHMC (850)434 8903 or (650)494 3973
>> 40 South Alcaniz St. (850)202 4416 office
>> Pensacola (850)202 4440 fax
>> FL 32502 (850)291 0667 mobile
>> phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
>>
>>
>>
>>
>>
>>
>
>
Received on Saturday, 3 July 2010 04:13:21 UTC