- From: Christopher St John <ckstjohn@gmail.com>
- Date: Tue, 24 Feb 2009 10:30:58 -0600
- To: public-lod@w3.org
I'm looking for feedback/pointers on best practices for finding objects in the Linked Data cloud given a geographic area of interest. Tom Heath's excellent Linked Data tutorial in Austin last week inspired me to do a quick Linked Data-based iPhone application. Think DBpediaMobile[1], only with a very different user interface. I spent some time researching the topic, but I was having a hard time figuring out what the general consensus was (or if there was one yet) I'd be happy to summarize responses into a FAQ answer. The DBpediaMobile paper[2] says: "The map view is built from RDF triples obtained by sending the currently visible area ... to the server, where they are rewritten as a SPARQL query and issued to a Virtuoso server that hosts DBpedia’s geocoordinates..." DBpediaMobile uses GeoNames data, and geonames has an API with a query called "findNearby" that looks promising, but I'm assuming that's "cheating". Calling out to an API breaks the idea of linking within the data, and means that you can't browse through without special integration code. There are proposed extensions to SPARQL to handle spatial semantics[3]. I suspect that would solve the "cheating" issue (because the query would presumably be generic enough to work with any possible data source), but GeoNames doesn't appear to handle any SPARQL at all. (I think) But the excerpt form the paper indicates that the public GeoNames database is not being used. Instead the data has been loaded into a private datastore, presumably one that supports special spatial SPARQL queries? Is that the case? I can always just load up whatever data I need into PostgreSQL (which has excellent geodata support) and drop down into SQL queries, but that seems against the spirit of the thing. And of course at that point it's not really Linked Data at all because it's not on the web, or shared, or RDF. Feedback/hints/obvious-things-I-missed/ corrections-to-misapprehensions greatly appreciated. -cks [1] http://wiki.dbpedia.org/DBpediaMobile actually seems to work pretty well on an iPhone, but there's no GPS info and i'd like to see a native app instead of something running in the browser. And what I have in mind has a totally different UI. [2] http://beckr.org/wp-content/uploads/DBpediaMobile.pdf [3] http://data.semanticweb.org/workshop/terra_cognita/2008/paper/main/1/html -- Christopher St. John http://praxisbridge.com
Received on Tuesday, 24 February 2009 16:31:39 UTC