- From: Aldo Gangemi <aldo.gangemi@cnr.it>
- Date: Wed, 14 May 2008 23:24:38 +0200
- To: "Michael F Uschold" <uschold@gmail.com>
- Cc: Aldo Gangemi <aldo.gangemi@cnr.it>, Tim Berners-Lee <timbl@w3.org>, Sören Auer <auer@informatik.uni-leipzig.de>, Semantic Web Interest Group <semantic-web@w3.org>, Chris Bizer <chris@bizer.de>, Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>, Kingsley Idehen <kidehen@openlinksw.com>, "Fabian M. Suchanek" <f.m.suchanek@gmail.com>, Tim Berners-Lee <timbl@csail.mit.edu>, Jim Hendler <hendler@cs.rpi.edu>, Mark Greaves <markg@vulcan.com>, georgi.kobilarov@gmx.de, Jens Lehmann <lehmann@informatik.uni-leipzig.de>, Richard Cyganiak <richard@cyganiak.de>, Frederick Giasson <fred@fgiasson.com>, Michael Bergman <mike@mkbergman.com>, Conor Shankey <cshankey@reinvent.com>, Kira Oujonkova <koujonkova@reinvent.com>
> • 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] http://www.ibiblio.org/hhalpin/irw2006/vpresutti.pdf from IRW workshop: 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 Thursday, 15 May 2008 08:18:59 UTC