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Re: National Identification Number URIs ( NIN URIs )

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Tue, 09 Mar 2010 07:00:49 -0500
Message-ID: <4B963871.1030807@openlinksw.com>
To: Hugh Glaser <hg@ecs.soton.ac.uk>
CC: Bernhard Schandl <bernhard.schandl@univie.ac.at>, Peter Ansell <ansell.peter@gmail.com>, Aldo Bucchi <aldo.bucchi@gmail.com>, Linked Data community <public-lod@w3.org>
Hugh Glaser wrote:
> I have found this a very interesting discussion, thinking about the Linked
> Data World at large as well as what others think - thanks.
> Sorry this moved away from the important discussion about how to identify
> people, both as a technical and a socio issue - my fault.
>   
Hugh,

Nice discussion, I don't think anyone found it divergent or distracting :-)

As per usual, you triggered broader discussion of some issues that have 
been rumbling under the surface for a while.

I am sure Aldo is much clear about options for easy generation of 
Identifiers etc..

Kingsley
> On 09/03/2010 09:12, "Bernhard Schandl" <bernhard.schandl@univie.ac.at>
> wrote:
>
>   
>> Peter,
>>
>>     
>>> It is a good thing that the subject URI is an HTTP URI available from
>>> your server but that is only the start of the story. The rest of the
>>> story needs other servers to give your data more context.
>>>
>>>       
>>>>> In your example the fact that there
>>>>> is a link can only be figured out using some external service that
>>>>> knows about both data sources.
>>>>>           
>>>> Sure. Before I can add a link to any data set, I have to detect it using
>>>> some heuristics. Shared URN/DOI/... identifiers seem a valid approach for
>>>> this -- think of ISBN numbers.
>>>>         
>>> Sharing identifiers is a good idea, but it isn't Linked Data as yet...
>>>       
>> I'm talking of the *preconditions* for linking data, based on shared
>> identifiers. And once I have these identifiers, why not publish them alongside
>> the dereferenceable URIs.
>>     
> Being able to work out what a dereferenceable URI means is indeed a
> pre-condition for linking data, and also in the Linked Data, this is
> achieved by dereferencing and examining the RDF returned.
> And finding a URN, doi, isbn, mailto, etc. is a very good way of
> communicating that information.
> However, for me in the Linked Data world, such URIs are no more an
> *identifier* than "Hugh Glaser", or the title of a book, (or even the URL of
> one of my homepages) simply because the access mechanism is unclear, and
> even if I do try to look it up I am unlikely to get RDF (at least at
> present).
> They are more useful in general, of course, because they are less likely to
> be ambiguous, but it is only a matter of degree.
>   
>>>>> If your server was Linked Data and not
>>>>> just an HTTP URI based RDF database then it would link out using HTTP
>>>>> URI's and both servers could be directly explored without some
>>>>> external service.
>>>>>           
>>>> Once the link has been detected, I can of course add it to both data sets.
>>>> Well, the owner of the datasets can.
>>>>         
>>> This is Linked Data, when the dataset owners discover the mutual
>>> references and link out from their HTTP URI's to the other datasets
>>> HTTP URI's.
>>>       
>> Why only the dataset owners? A third party that is aware of both data sets is
>> enabled to discover these links, too.
>>     
> I agree entirely, although the dataset owner is in a prime position to seed
> the activity, and also may have other implicit knowledge that is useful to
> help to get the links right.
>   
>>> It was enabled by sharing the property, and then having
>>> others discover it. Just sharing the URN property isn't Linked Data as
>>> people have no way of resolving the URN that is referenced to more
>>> information.
>>>       
>> Again, it's a precondition to link data.
>>
>>     
>>> It could also have been shared in another way using Inverse Functional
>>> Properties (IFP) so that the URN scheme need not have been created.
>>>       
>> The URN schema for ISBN already exists [1], and several others exist (e.g.,
>> SWIFT [2]), why should we throw them away?
>>
>> [1] <http://www.faqs.org/rfcs/rfc3187.html>
>> [2] <http://www.faqs.org/rfcs/rfc3615.html>
>>
>>     
>>> There is no automatic HTTP based way of knowing which datasets may
>>> have relevant links in either case,
>>>       
>> One could use indices to find other occurrences of the same URN. When they are
>> linked via owl:sameAs, the linking can be fully automatized.
>>
>>     
>>> so serving up the statements on
>>> your dataset is very useful for discovery, I wasn't meaning to say
>>> that was a bad thing. Just emphasising the full story for Linked Data.
>>>       
>> I got that :-) 
>>
>> My point is simply that not *every* URI in a Linked Data context needs to be
>> dereferenceable. When there are established URN schemes in place (like it is
>> the case for ISBN numbers), why not reuse them instead of packing them in a
>> literal (is there a datatype for ISBN numbers?) and publish them to simplify
>> linking for others? This seems to make more sense to me than only relying on
>> URN-to-HTTPURI mappings, which I can still do, as long as I publish the
>> "original" identifier in its "native" URN form.
>>     
> I have a feeling that the issue here may be the same as how to represent the
> address of someone's pure html home page in RDF.
> It is a URL and hence a URI. But it is not dereferenceable to RDF.
> A purist might say that it is not a Linked Data URI (doesn't return RDF),
> and so should be a string, hopefully with a useful type on it.
> But for others it is a resource, and so can comfortably be a URI in RDF.
> And having it as a resource enables it to be used in a more convenient way
> for the sort of thing that we are discussing.
> So dereferencing one of your Linked Data URIs will return some RDF that has
> resources (URIs) that are not dereferenceable to RDF.
> And these will be very helpful to people/agents who are trying to add
> linking to the world.
>
> Hopefully that is sufficiently closely related to your comments to make
> sense?
> And I am pleased to agree, although I might lean more to the purist side :-)
>
> By the way, in the original question, there seemed to be a suggestion which
> I guess I misunderstood, that an RDF store that effectively only published
> non-dereferenceable URIs, and accessed as a query service, was in some sense
> doing Linked Data. I would have found that very hard to agree with.
>
> Best
> Hugh 
>   
>> Best
>> Bernhard
>>
>>     
>
>
>   


-- 

Regards,

Kingsley Idehen	      
President & CEO 
OpenLink Software     
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen 
Received on Tuesday, 9 March 2010 12:01:20 UTC

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