- 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