- From: Young,Jeff (OR) <jyoung@oclc.org>
- Date: Fri, 17 Feb 2012 14:24:26 -0500
- To: "Hugh Glaser" <hg@ecs.soton.ac.uk>, <public-lod@w3.org>
Hugh, I commonly use PURLs when I'm modeling RDF vocabularies as described here: http://www.w3.org/TR/swbp-vocab-pub/#purls This allows me to prototype the vocabulary on my workstation without concern for where it ultimately ends up. Any instance data I generate along the way will remain unaffected since I've used PURL as the vocabulary namespace. Jeff > -----Original Message----- > From: Hugh Glaser [mailto:hg@ecs.soton.ac.uk] > Sent: Friday, February 17, 2012 1:48 PM > To: public-lod@w3.org > Subject: PURLs don't matter, at least in the LOD world > > (Sorry if there is a paper/discussion on this that I have missed > somewhere. And I may have some of this wrong, as I have essentially not > used PURLs.) > M Scott Marshall and others' comments have prompted me to put pen to > paper and ask what the list thinks on this. > > It has long puzzled me why people seem to think that PURLs (and > Handles, etc.) solve some actual problem. > Leaving aside the question of whether it actually adds extra fragility > as to whether purl.org will continue to exist. > (Personally I would bet the Library of Congress will last longer than > purl.org, but I would have to wait too long to collect on the bet to > make it worthwhile.) > > In the Linked Data world, at least, what does a PURL give protection > from? > > Let's say I have http://dbpedia.org/resource/Tokyo. I can: > a) Use the URI without any URI resolution at all, and it is really > useful to do so (as commented, foaf:name is used a lot, and it does not > depend on anything being at the other end to resolve to); > b) I can resolve to find out what DBPedia thinks it "means" (returns as > RDF); > c) I can use it as an ID for another source to find out what that other > source thinks it "means". > > Now let's say dbpedia.org goes Phut! > What I lose is facility (b) > > What happens if I have http://purl.org/dbpedia/Tokyo, which is set to > go to http://dbpedia.org/resource/Tokyo? > I have (a), (b) and (c) as before. > Now if dbpedia.org goes Phut!, we are in exactly the same situation - > (b) gets lost. > > Both of these situation can be fixed by persuading someone (the > registrar for dbpedia.org or the purl.org organisers respectively) to > allow someone else to take over purl.org/dbpedia or dbpedia.org > respectively. > But once dbpedia.org goes Phut!, you get a dead link whatever you do, > until someone takes it over. > > Not much to be gained for the overheads of having the purl? > > I can see that in the Web of Text, a URI that has gone 404 is rather > painful. > And I know that people who have curated data find dying links painful, > and seem to find Handles etc some sort of comfort for their concerns, > even though they don't necessarily solve the perceived problem, in my > view. > But in the Web of Data, given a good guess at somewhere else (such as > the LoC, or even the Virtuoso endpoint or sameAs.org), I stand a good > chance of finding a skos:*Match or even an owl:sameAs that will get me > back on track again. > > Is there something I am missing about PURLs? > > Best > Hugh > -- > Hugh Glaser, > Web and Internet Science > Electronics and Computer Science, > University of Southampton, > Southampton SO17 1BJ > Work: +44 23 8059 3670, Fax: +44 23 8059 3045 > Mobile: +44 75 9533 4155 , Home: +44 23 8061 5652 > http://www.ecs.soton.ac.uk/~hg/ > >
Received on Friday, 17 February 2012 19:25:46 UTC