- From: Philip Taylor <excors+whatwg@gmail.com>
- Date: Fri, 15 May 2009 20:30:23 +0100
On Fri, May 15, 2009 at 6:25 PM, Shelley Powers <shelleyp at burningbird.net> wrote: > The most important point to take from all of this, though, is that link rot > within the RDF world is an extremely rare and unlikely occurrence. That seems to be untrue in practice - see http://philip.html5.org/data/rdf-namespace-status.txt The source data is the list of common RDF namespace URIs at http://ebiquity.umbc.edu/resource/html/id/196/Most-common-RDF-namespaces from three years ago. Out of those 284: * 56 are 404s. (Of those, 37 end with '#', so that URI itself really ought to exist. In the other cases, it'd be possible that only the prefix+suffix URIs are meant to exist. Some of the cases are just typos, but I'm not sure how many.) * 2 are Forbidden. (Of those, 1 looks like a typo.) * 2 are Bad Gateway. * 22 could not connect to the server. (Of those, 2 weren't http:// URIs, and 1 was a typo. The others represent 13 different domains.) (For the URIs which returned Redirect responses, I didn't check what happens when you request the URI it redirected to, so there may be more failures.) Over a quarter of the most common namespace URIs don't resolve successfully today, and most of those look like they should have resolved when they were originally used, so link rot seems to be common. (Major vocabularies like RSS and FOAF are likely to exist for a long time, but they're the easiest cases to handle - we could just pre-define the prefixes "rss:" and "foaf:" and have a centralised database mapping them onto schemas/documentation/etc. It seems to me that URIs are most valuable to let any tiny group make one for their rarely-used vocabulary, and be guaranteed no name collisions without needing to communicate with a centralised registry to ensure uniqueness; but it's those cases that are most vulnerable to link rot, and in practice the links appear to fail quite often.) (I'm not arguing that link rot is dangerous - just that the numbers indicate it's a common situation rather than an extremely rare exception.) -- Philip Taylor excors at gmail.com
Received on Friday, 15 May 2009 12:30:23 UTC