I don't speak for Freebase, but I know a fair bit about it, so I'll provide the background that I'm familiar with.
There are two different issues here: 1. Which identifier(s) are used: guid, mid, or human readable /en/... key 2. The format of the identifier, ie whether they have embedded dots (.) or slashes (/) GUIDs are bare metal identifiers and should never be used because they don't survive merges, splits, etc. The /en identifiers used to be given preference, but now are deprecated and MIDs are recommended for long term linking (plus no new /en identifiers have been minted in a long time, so you need to be able to handle MIDs). MIDs are similar to GUIDs, *except* that they move with topics which are merged, so they're more stable. As for separators, the Freebase RDF endpoint has always converted the native slashes (/) to dots (.) in identifiers. I'm not 100% certain, but I think the slashes caused problems in certain processing frameworks (or perhaps they just wanted the identifiers to be treated as an opaque string rather than a namespace hierarchy). DBpedia should, in my opinion, always be using MIDs for the canonical link and they should used the dotted form in preference to slashes. If you want an official recommendation, you should probably ask Jason Douglas or Shawn Simister (hopefully they won't say anything too wildly different than the above). Tom On Tue, Jul 10, 2012 at 10:41 AM, Jona Christopher Sahnwaldt <[email protected]> wrote: > I just looked through older DBpedia releases. I think we started > publishing Freebase links in 3.1. Until 3.5, we used URIs like > http://rdf.freebase.com/ns/guid.9202a8c04000641f80000000002d1e19 . In > 3.6 and 3.7, we used URIs like http://rdf.freebase.com/ns/m/01006r . > In 3.8, we will use http://rdf.freebase.com/ns/m.01006r . > > All these URIs can be resolved, but they are not the 'canonical' URIs. > The ones with the dot also aren't 'canonical': the page > http://rdf.freebase.com states that Freebase RDF IDs look like > http://rdf.freebase.com/ns/en.steve_martin . On the other hand, the > explanations on http://wiki.freebase.com/wiki/Mid and > http://wiki.freebase.com/wiki/Id seem to say that mids like '/m/0p_47' > are more stable than ids like 'steve_martin', and while all topics > have a mid, some don't have an id. So it seems best to use URIs like > http://rdf.freebase.com/ns/m.0p_47 . > > Also, extracting URIs like http://rdf.freebase.com/ns/en.steve_martin > would require a bit more coding, but if people (someone at Freebase?) > think DBpedia should do that, we could probably add it for 3.9. > > Christopher > > > > On Tue, Jul 10, 2012 at 2:57 PM, Tom Morris <[email protected]> wrote: >> I know it has been correct in the past so this only effects some subset of >> the releases (not sure which ones). >> >> Tom >> >> On Jul 10, 2012 8:50 AM, "Jona Christopher Sahnwaldt" <[email protected]> >> wrote: >>> >>> DBpedia linked to the wrong URI, but that has been fixed. In the >>> upcoming release, we'll use the dot. Thanks for the report! >>> >>> Christopher >>> >>> On Tue, Jul 10, 2012 at 12:21 AM, Juan Sequeda <[email protected]> >>> wrote: >>> > I'm fwding my question to this mailing list. >>> > >>> > Juan Sequeda >>> > +1-575-SEQ-UEDA >>> > www.juansequeda.com >>> > >>> > >>> > ---------- Forwarded message ---------- >>> > From: Juan Sequeda <[email protected]> >>> > Date: Sun, Jul 8, 2012 at 7:09 PM >>> > Subject: question about dbpedia and freebase interlinking >>> > To: public-lod <[email protected]> >>> > >>> > >>> > All, >>> > >>> > It seems like there is a mismatch with the links between dbpedia and >>> > freebase. >>> > >>> > Take for example http://dbpedia.org/resource/Austin,_Texas >>> > >>> > The owl:sameAs link is to: http://rdf.freebase.com/ns/m/0vzm however the >>> > RDF >>> > triples that are returned have the URI http://rdf.freebase.com/ns/m.0vzm >>> > (not that it has a period (.) instead of a slash (/)). >>> > >>> > Did freebase change the URIs? Or is DBpedia linking to the wrong URI? >>> > >>> > Juan Sequeda >>> > +1-575-SEQ-UEDA >>> > www.juansequeda.com >>> > >>> > >>> > >>> > ------------------------------------------------------------------------------ >>> > Live Security Virtual Conference >>> > Exclusive live event will cover all the ways today's security and >>> > threat landscape has changed and how IT managers can respond. >>> > Discussions >>> > will include endpoint security, mobile security and the latest in >>> > malware >>> > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>> > _______________________________________________ >>> > Dbpedia-discussion mailing list >>> > [email protected] >>> > https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion >>> > >>> >>> >>> ------------------------------------------------------------------------------ >>> Live Security Virtual Conference >>> Exclusive live event will cover all the ways today's security and >>> threat landscape has changed and how IT managers can respond. Discussions >>> will include endpoint security, mobile security and the latest in malware >>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>> _______________________________________________ >>> Dbpedia-discussion mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Dbpedia-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dbpedia-discussion
