RE: Dataset vocabularies vs. interchange vocabularies

This mention of owl:sameAs reminds me of the mention of the "sameAs issue", at ISWC, that has developed in the semantic web arena.
I can imagine what this issue is, but am not 100% sure, so can anyone explain this issue to me?

Kevin Richards

-----Original Message-----
From: [] On Behalf Of Harry Halpin
Sent: Friday, 28 November 2008 2:05 a.m.
To: Richard Cyganiak
Cc: John Graybeal;; Semantic Web
Subject: Re: Dataset vocabularies vs. interchange vocabularies

On Thu, 27 Nov 2008, Richard Cyganiak wrote:

> On 26 Nov 2008, at 21:53, John Graybeal wrote:
> <snip>
>> would you agree that duplicating a massive set of URIs for 'local technical
>> simplification' is a bad practice? (In which case, is the question just a
>> matter of scale?)
> You are asking me if 'local technical simplification' is a good reason or a
> bad reason for duplicating URIs? Uh, I guess it depends...
> My point was this: The key benefits of URI re-use can also be obtained by
> minting your own URIs and linking them to existing URIs via adequate RDF
> properties. And that practice can have additional practical/implementation
> benefits (and costs). Hence, consider both options; there's no reason to
> knee-jerk against creating new identifiers.

I agree in theory with Richard, but in practice with John. The key
benefits of URI re-use can  only be gained by using multiple URIs if we
have "adequate URI properties"  (i.e. owl:sameAs?) and given  an adequate
reasoning system  that can identify the same URIs in any data  set -
including large ones -  where we want to merge data using these  "inferred
to be the same" URIs.

To my knowldge, we have neither adequate URI properties or working
reasoning services, at least for the end-user. Now perhaps this will
change, but if not, why not re-use URIs?

If we do have adequate URI properties besides the infamous owl:sameAs,
please point me to them. And while at ISWC there was clearly lots of work
on large-scale identity management trying to discover URI equivalences via
inference, I'm not sure how well that works right now.

Furthermore, there's the question of what URI  to use in the output if one
is identifying URI's to be the same and one wants to re-use the merged data.


  > Best,
> Richard
>> John
>> --------------
>> John Graybeal   <>  -- 831-775-1956
>> Monterey Bay Aquarium Research Institute
>> Marine Metadata Interoperability Project:


        Harry Halpin
        Informatics, University of Edinburgh

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Received on Friday, 28 November 2008 00:12:00 UTC