- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Sun, 24 May 2009 19:32:51 -0400
- To: Hugh Glaser <hg@ecs.soton.ac.uk>
- CC: "richard.hancock@3kbo.com" <richard.hancock@3kbo.com>, "public-lod@w3.org" <public-lod@w3.org>
Hugh Glaser wrote: > An interesting question - should be a classic for Linked Data. > As I understand it, your primary problem for New Zealand is that there is no reliable information about the administrative geography. > It doesn't help for New Zealand (!), but for the UK you could use the Ordnance Survey's, which can be found in RDF via > http://osdir.com/ml/web.semantic.linking-open-data/2008-05/msg00011.html > We have made it linked data at os.rkbexplorer.com, with a SPARQL endpoint if you want it. > (If people are doing this sort of thing (if you thought of doing some of it yourself), then reusing the OS ontology might be a good idea.) > > For the UK, it would be a case of jumping (follow-your-nose) backwards and forwards between the os and dbpedia, I suggest, using the os to find the inclusion and dbpedia to find the knowledge. > This afternoon I did a bunch of links between them (the bigger areas and towns), to let you have a go if you like, and these can be found at our os coreference service (crs) at > http://os.rkbexplorer.com/crs/ > > By the way, if you want an easy way of finding out what URIs might tell you what is known about a particular place (or anything), you could try our sameAs service at > http://www.rkbexplorer.com/sameAs/?uri= > So New Zealand would be > http://www.rkbexplorer.com/sameAs/?uri=http://dbpedia.org/resource/New_Zealand > And Wellington http://www.rkbexplorer.com/sameAs/?uri=http://dbpedia.org/resource/Wellington > and you can follow-your-nose from there. > Hugh, Assuming you sent this response before mine re. http://lod.openlinksw.com . How does the following not resolve this problem: 1. Go to http://lod.openlinksw.com 2. Enter pattern: New Zealand 3. Use "Type" and/or "Property" to locate what you want 4. Once found, click on "statistics" link Kingsley > Best > Hugh > > On 24/05/2009 08:19, "richard.hancock@3kbo.com" <richard.hancock@3kbo.com> wrote: > > Hi all, > > I am wondering what are the best queries to run against the various LOD > datasets in order to get an idea of what Linked Data is currently > available for a specific country, e.g. New Zealand. > > My plan was to start with Dbpedia and move out from there but so far my > Dbpedia queries so far haven't yielded the results I was hoping for. > > My initial reasoning was that I could use the Dbpedia country URI ( i.e. > <http://dbpedia.org/resource/New_Zealand> ) as the beginning point for my > search and get a list of properties relating things to New Zealand using > > SELECT DISTINCT ?p > FROM NAMED <http://dbpedia.org> > WHERE { > ?s ?p <http://dbpedia.org/resource/New_Zealand> . > } > > and a list of New Zealand properties using > > SELECT DISTINCT ?p > FROM NAMED <http://dbpedia.org> > WHERE { > <http://dbpedia.org/resource/New_Zealand> ?p ?o . > } > > The first thing I looked for were properties that would let me find towns > and cities in New Zealand. > > When I couldn't find obvious properties relating New Zealand towns and > cities to New Zealand I tried taking the URI of a specific city, > Wellington to see what properties linked it to New Zealand. > > The query below shows that no property linked Wellington to New Zealand. > > SELECT * > FROM NAMED <http://dbpedia.org> > WHERE { > <http://dbpedia.org/resource/Wellington> ?p > <http://dbpedia.org/resource/New_Zealand> . > } > > gives no results. > > Going the other way showed that Wellington was the capital of New Zealand > but I was also expecting to see another property indicating that > Wellington was a city of New Zealand. I had hoped to find the second > property so that I could use it to find all other cities and towns within > New Zealand. > > SELECT * > FROM NAMED <http://dbpedia.org> > WHERE { > <http://dbpedia.org/resource/New_Zealand> ?p > <http://dbpedia.org/resource/Wellington>. > } > > indicates that New_Zealand has a capital via > <http://dbpedia.org/property/capital> of Wellington > > The best indication that Wellington is located in New Zealand was found > using the location property. > > SELECT * > FROM NAMED <http://dbpedia.org> > WHERE { > <http://dbpedia.org/resource/Wellington> > <http://dbpedia.org/property/location> ?o . > } > > gives the literal "Wellington, New Zealand"@en. > > A scenario similar to the one between Wellington and New Zealand exists > between Berlin and Germany but here the literal value of the location > property proves less useful > > SELECT ?location > FROM NAMED <http://dbpedia.org> > WHERE { > <http://dbpedia.org/resource/Berlin> > <http://dbpedia.org/property/location> ?location . > } > > gives the literal "Berlin"@en > > At this point I thought it was time to ask for help. > > For the current Linked Data sets what is the best approach to take when > seeking to find what information has already been published for a specific > country ? > > Depending on what you are looking for are some datasets better starting > points than others? E.g. for finding the towns and cities is geonames > (http://sws.geonames.org/) ,CIA Factbook or some other dataset, a better > starting point? > > For Dbpedia are there plans to migrate properties like location > <http://dbpedia.org/property/location> which currently use literals to use > URIs instead? > > Cheers, > > Richard Hancock > > > > > > > > > > > > > > -- Regards, Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen President & CEO OpenLink Software Web: http://www.openlinksw.com
Received on Sunday, 24 May 2009 23:33:28 UTC