Hugh Glaser said: At the bottom you will se that an agent can import this as ntriples owl:sameAs - we have nothing against owl:sameAs, if that is what the agent wants to do, but the inference decision can be up to them. This idea has a lot of merit, IMHO. It allows people a safe way to say that URIs are closely related, w/o going so far is making them logically equivalent. And you offer a convenient way to convert the co-references to sameAs. This could make life a lot easier for folk who wish to load in a variety of datasets and do reasoning on them. Pity I won't make it to the upcoming workshop. Michael Michael On Thu, May 15, 2008 at 11:59 AM, Hugh Glaser <hg@ecs.soton.ac.uk> wrote: > Michael, > Many thanks for asking the question. > It is very exciting to see this discussion so active. > I have been trying to get to the front of the messages to say something, > but they just keep coming in! > To answer you email: > Yes, we have an infrastructure (the Consistent Reference Service, CRS) with > which we have been trying to manage co-reference between a bunch of > independent SW sites to allow applications to do what they need. It has gone > through quite a few revisions over the last four years or so. > > > On 15/05/2008 00:25, "Michael F Uschold" <uschold@gmail.com> wrote: > > Aldo notes the problems with using owl:sameAs to mean similarity. Such uses > are often incorrect, and Aldo suggests using something like rdfs:seeAlso, > skos:related, instead. These relations are too weak, unfortunately. > > There is an interesting proposal for managing URI snyonyms that attempts to > have a middle ground, weaker than owl:sameAs, but much stronger than > rdfs:seeAlso or skos:related. They suggest an infrastructural approach > [apparently] outside the logic for managing URI synonyms. It is a quite > clever approach, but still has some challenges. Here are portions of a note > I just sent the authors of a paper, which relates to this question. > > Afraz, Hugh and Ian: > > I just read your workshop paper: > Managing URI Synonymity to Enable Consistent Reference on the Semantic Web > <http://eprints.ecs.soton.ac.uk/15614/1/camera-ready.pdf>< > http://eprints.ecs.soton.ac.uk/15614/1/camera-ready.pdf> > > > 1. I wholeheartedly agree that owl:SameAs is too strong in many cases. A > weaker relation is needed. However, you don't offer weaker relation and give > it semantics. Instead, you do a kind of sleight of hand and remove it from > the logic. Without a semantics, what is a system developer to do with the > fact that two URIs are in the same bundle? What are the inferential > impliciations? > 2. > 3. Example: IMHO it is a bad idea to say that Spain the political entity > is the same as Spain the geopolicial region. This ontological distinction > has been clear documented in DOLCE, for example. They are different, and > should have different URIs. Conflating them will cause problems. Of > course, making this and many other ontologically 'sound' distinctions can > cause its own problems, by adding complexity -- a tradeoff. Without any > semantics of inCRS_Bundle, there is no way to tell if it is semantically > correct. > 4. Do you have any idea of the scalability of this approach? > > Michael > > > > On Wed, May 14, 2008 at 2:24 PM, Aldo Gangemi <aldo.gangemi@cnr.it> wrote: > * Problem 2) even if you can find the links, prolific use of > owl:sameAs will create computational problems. > > > > Michael, > > there is an item related to Problem 2), already discussed on LOD and > elsewhere last year, i.e. the use of > owl:sameAs, which is a formal relation of identity, to denote generic > "similarity", or even "relatedness" > between two entities. > > owl:sameAs is great to co-reference persons, places, etc. It is buggy when > used to relate e.g. foaf:Person > instances to persons' homepages, or a city as from Cyc to a wikipedia > article of that city (as done in DBpedia). > > In previous discussions, besides some weak good practices [1], I found no > attempt to discourage its use for similarity. > This use is not needed. We can use e.g. rdfs:seeAlso, skos:related, or any > other local relation instead. > > It is reasonable, as Richard Cyganiak wrote at the time, that we have to > work around the quirks [2], > nonetheless, if there is no real need, why should we work around the quirks > caused by a pointless identity > assumption? > > Notice that ignoring owl:sameAs is not a good solution. We need some > trade-off between simplicity > and formality. A basic similarity relation is perfect, and then those > triples can be worked out automatically, > by means of appropriate metamodels, e.g. as proposed in [3]. > > Aldo > > [1] Bernard Vatant suggested some good practice of mutual linking: > > http://universimmedia.blogspot.com/2007/07/using-owlsameas-in-linked-data.html > > [2] Cyganiak quote: > People who want to re-use your data will learn to work around its quirks > and idiosyncrasies. > Dealing with the quirks is a part of re-using data, it always was, and it > always will be. > > > [3] MailScanner has detected definite fraud in the website at " > www.ibiblio.org". Do not trust this website: > http://www.ibiblio.org/hhalpin/irw2006/vpresutti.pdf < > http://www.ibiblio.org/hhalpin/irw2006/vpresutti.pdf>< > http://www.ibiblio.org/hhalpin/irw2006/vpresutti.pdf> from IRW workshop: > MailScanner has detected definite fraud in the website at "www.ibiblio.org". > Do not trust this website: http://www.ibiblio.org/hhalpin/irw2006/ < > http://www.ibiblio.org/hhalpin/irw2006/>< > http://www.ibiblio.org/hhalpin/irw2006/> > > > _________________________________ > > Aldo Gangemi > > Senior Researcher > Laboratory for Applied Ontology > Institute for Cognitive Sciences and Technology > National Research Council (ISTC-CNR) > Via Nomentana 56, 00161, Roma, Italy > Tel: +390644161535 > Fax: +390644161513 > aldo.gangemi@cnr.it > > http://www.loa-cnr.it/gangemi.html > > icq# 108370336 > > skype aldogangemi > > > > >Received on Friday, 16 May 2008 00:03:07 GMT
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