- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Tue, 27 Apr 2010 17:38:24 +0200
- To: Hugh Glaser <hg@ecs.soton.ac.uk>
- Cc: geonames <geonames@googlegroups.com>, Linking Open Data <public-lod@w3.org>
- Message-ID: <s2y9d93ef961004270838xaa0eda6fwb64e4deb83c929d0@mail.gmail.com>
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 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) > 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. BTW currently working in connection with Gerard de Melo at http://lexvo.orgre. 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 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%2Fperhaps? > > This seems like a good idea. Considering that 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> . The 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> , 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> 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> 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> 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-concordance, > 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 > -- Bernard Vatant Senior Consultant Vocabulary & Data Engineering Tel: +33 (0) 971 488 459 Mail: bernard.vatant@mondeca.com ---------------------------------------------------- Mondeca 3, cité Nollez 75018 Paris France Web: http://www.mondeca.com Blog: http://mondeca.wordpress.com ----------------------------------------------------
Received on Tuesday, 27 April 2010 15:38:58 UTC