Phillip, hello. On 2013 May 9, at 13:09, Phillip Lord wrote:
> Norman Gray <[email protected]> writes: >>> I am not completely familiar with DOI. Am I right, that it more or less >>> provides the same service as http://purl.org . >>> DOI links on the resource-level. You would still need frag ids to link to >>> parts. >>> Firefox can actually handle this: >>> http://dx.doi.org/10.1038%2Fscientificamerican1210-80#atl >> >> It's not the same thing as purl.org. > > The mechanism by which DOIs and purls are resolved is more or less > identical. Under the hood, DOIs use handles, purl.org uses a triple > store. In practice, users don't interact with either directly. Well, yes and no. The distinction I was thinking about was that PURLs are _defined_ in terms of an HTTP redirect (the triple store behind it is an implementation detail), whereas DOIs are defined in terms of the underlying, distributed, Handle system. There, the dx.doi.org URL is 'just' a convenience layer on top of the 'real' API. I don't think this is just a quibble, because this, plus the different sustainability model, effectively gives the DOIs different persistence properties from PURLs. Whether those different properties are _practically_ different is of course a different question. Myself, I'm broadly doubtful that there's a massive practical difference; but although I'm unpersuaded by it, I can see the force of the argument that the DOI sustainability model is of crucial importance. The other argument for DOIs is that 'http:' refers to a transport protocol, which is being hijacked as an identifier scheme, and will presumably be replaced by whatever replaces HTTP over the coming decades. I think this argument, also, is initially attractive but unpersuasive in detail, but it doesn't even arise for 'doi:', which is an identifier scheme by definition. >>> If I am right, DOI also wouldn't be able to provide links to the 40 >>> million mentions contained in the Wiki links corpus: >>> http://techcrunch.com/2013/03/08/google-research-releases-wikilinks-corpus-with-40m-mentions-and-3m-entities/ >>> That's 40 million DOIs .... >> >> I don't there would be such DOIs, unless someone has spent quite a lot of >> money registering them. > > > A purl would be much better in this case anyway, since purls support > partial redirection, which to my knowledge, DOIs do not. With DOIs you > would need 40 million DOIs. With purls, you would create a single > partial redirect purl and handle the rest locally. I've been on the fringes of Datacite discussions, so don't know the fully up-to-date details, but I believe that one of the use-cases, in discussions about the pricing structure, is the case where someone _does_ want to register millions of DOIs per year (or billions: what about a DOI for every LHC event?). I _think_ the resolution to the 40M DOIs question is "don't do that, then", but the question has crossed the Datacite people's minds, and the different Datacite registries have (I understand) different pricing models for different DOI volumes. All the best, Norman -- Norman Gray : http://nxg.me.uk SUPA School of Physics and Astronomy, University of Glasgow, UK
