- From: Hugh Glaser <hg@ecs.soton.ac.uk>
- Date: Wed, 12 May 2010 20:00:32 +0000
- To: Bernard Vatant <bernard.vatant@mondeca.com>
- CC: geonames <geonames@googlegroups.com>, Linking Open Data <public-lod@w3.org>
Thanks Bernard, Always good to be discussing things around a common basis. Sorry for the slow reply very intermittent connectivity. On 27/04/2010 16:38, "Bernard Vatant" <bernard.vatant@mondeca.com> wrote: > Hi Hugh > > 2010/4/27 Hugh Glaser <hg@ecs.soton.ac.uk> >> Thanks Bernard. >> Yes, I think the problems you raise are valid. >> Just a short response. >> In some sense I consider sameas.org <http://sameas.org> to be a discovery >> service. > > Indeed, so do I. The known issue is the overload of owl:sameAs, but you have > an excellent presentation today of Pat Hayes and Harry Halpin just coming ... > (you are at ldow2010 I guess) I was, and enjoyed it. > >> This is in contrast to a service that might be called something more >> definitive. >> So I have taken quite a liberal view of what I will accept on the site. >> We have other services that are much more conservative in their view; in >> particular the ones we use for RKBExplorer. >> So what we are trying to do is capture a spectrum of views of what >> constitutes equivalence, which will always be a moveable feast. > > Agreed with all that. Maybe you could introduce a sameas ontology for > different flavours of equivalence, containing a single property sameas:sameas > of which owl:sameAs; owl:equivalent*, skos:*Match ... would be subproperties. > In that case the "liberal" clustering would use sameas:sameas and the more > conservative ones whatever fits. It is interesting you should say that. For many years we gathered equivalence information and republished against a more complex ontology - that was the "right" way to do it. Eventually I decided that the right way to do it was not the socio-technical right way to do it, and added the owl:sameas predicate and named the site sameas.org. (Although you can still ask sameas.org to give you a different predicate if you want, I think, but can't check.) I know using owl:sameas is the "wrong" way to do it, but when we did it the right way no-one showed any interest. I think we needed to go through this phase of publishing as owl:sameas, so that people would discover that it is problematic. In a more reflective state, I might observe the following: We have a community who work in URI equivalence who are looking for an ontology to capture the concepts. If I was to be called in as a consultant to this community I might go through a whole process of Knowledge Acquisition processes, using a bunch of tools. It is interesting that the URI community seems unable to capture the knowledge into a useable ontology, when perhaps we expect everyone else to be able to do the same thing for their areas of expertise. What would a knowledge acquisition expert recommend for this ontology, which we seem to think should be quite simply? Best Hugh > > BTW currently working in connection with Gerard de Melo at http://lexvo.org > re. semiotic approach to this issue, connecting vocabulary resources > (concepts, classes, whatever) through the terms they use. You might bring that > on ldow forum. > > Have fun Thanks: I am - on holiday! > > Bernard > > >> Best >> Hugh >> >> On 23/04/2010 16:14, "Bernard Vatant" <bernard.vatant@mondeca.com> wrote: >> >> Alexander : >> >> It would be useful to have a list of currently available mappings to >> GeoNames. It would be useful not only for people like me who create custom >> RDF datasets but also for people who want to contribute additional mappings. >> >> Seems a good idea >> >> Daniel : >> >> Re-publish your data with rdfs:seeAlso >> http://sameas.org/rdf?uri=http%3A%2F%2Fsws.geonames.org%2F2078025%2F perhaps? >> >> This seems like a good idea. Considering that geonames.org >> <http://geonames.org> <http://geonames.org> cannot dedicate (m)any >> resources to LOD mappings, those can be deferred to external services such as >> sameas.org <http://sameas.org> <http://sameas.org> . The sameas.org >> <http://sameas.org> <http://sameas.org> URI is easy to generate >> automatically from the geonames id. >> >> So far so good. But let's look at it closely. Someone has to feed this kind >> of recursive and iterative social process happening at sameas.org >> <http://sameas.org> <http://sameas.org> , but there is no provenance track, >> and the clustering of URIs will make with the time the concepts more and more >> fuzzy, and sameas.org <http://sameas.org> <http://sameas.org> a tool to >> create semantic black holes. >> >> It would be definitely better to have some clear declaration from Geonames >> viewpoint which of its three URIs for Berlin >> http://sws.geonames.org/2950159/, http://sws.geonames.org/6547383/ or >> http://sws.geonames.org/6547539/ should map to >> http://dbpedia.org/resource/Berlin. So far, neither does. >> >> From DBpedia side owl:sameAs declarations at the latter URI are as following >> (today) >> >> * opencyc:en/Berlin_StateGermany >> <http://sw.opencyc.org/2008/06/10/concept/Mx4rv77EfZwpEbGdrcN5Y29ycA> >> * fbase:Berlin >> <http://rdf.freebase.com/ns/guid.9202a8c04000641f80000000000094d6> >> * http://umbel.org/umbel/ne/wikipedia/Berlin >> * opencyc:en/CityOfBerlinGermany >> <http://sw.opencyc.org/2008/06/10/concept/Mx4rvVjrhpwpEbGdrcN5Y29ycA> >> * http://www4.wiwiss.fu-berlin.de/eurostat/resource/regions/Berlin >> * http://sws.geonames.org/2950159/ >> * http://data.nytimes.com/N50987186835223032381 >> >> So it seems DBpedia has decided to map its Berlin to the Geonames feature of >> type "capital of a political entity", subtype of "populated place". Why not? >> OTOH it also declares two equivalent in opencyc, one being a state and the >> other a city. If opencyc buys the DBpedia declarations, the semantic collapse >> begins >> >> Let's go yet closer to the black hole horizon ... >> >> http://sameas.org/html?uri=http%3A%2F%2Fdbpedia.org%2Fresource%2FBerlin >> >> ... yields 29 URIs including the previous ones ... >> >> If geonames.org <http://geonames.org> <http://geonames.org> had taken the >> time to map carefully its administrative features on the respective "city" >> and "state" opencyc resources, the three different URIs carefully coined to >> make distinct entities for Berlin as a populated place and the two >> administrative subdivisions bearing the same name, would be by the grace of >> DBpedia fuzziness crushed in the same sameas.org <http://sameas.org> >> <http://sameas.org> semantic black hole. >> >> Bottom line. Given the current state of affairs for geographical entities in >> the linked data cloud, geonames agnosticism re. owl:sameAs is rather a good >> thing. There are certainly more subtle ways to link geo entities at various >> level of granularity, and a lot of work to achieve semantic interoperability >> of geo entities defined everywhere. Things are moving forward, but it will be >> a long way and needin a lot of resources. Look e.g., at Yahoo! concordance >> http://developer.yahoo.com/geo/geoplanet/guide/api-reference.html#api-concord >> ance, which BTW also links to geonames id. >> >> In conclusion: >> >> YES Marc Wick is right to currently focus on data and data quality first. A >> tremendous set of data is available for free, take what you can and what you >> wish and build on it. If you want premium services, pay for it. Fair enough. >> >> YES it should be great to have geonames data/URIs more integrated, and better >> to the linked data economy. More complete descriptions at sws.geonames URIs, >> SPARQL endpoint etc. Bearing in mind that Geonames.org has no dedicated >> resources for it, who will care of that in a scalable way? What is the >> business model? Good questions. Volunteers, step forward :) >> >> Bernard > >
Received on Wednesday, 12 May 2010 20:01:34 UTC