Chuck,
You are absolutely right, there are many conflated issues being cross threaded in our discussions. Let's separate them.
Regarding use cases, we have developed several of them just before the first GUID meeting in 2006. Jessie made a comment back then that some use cases regarding taxon concepts were missing. There may be other cases missing. In any case they are at:
http://wiki.tdwg.org/twiki/bin/view/GUID/GUIDUseCases
If anyone want to discuss GUID use cases, please reply to this thread only.
Thanks!
Ricardo
Chuck Miller wrote:
I agree with Rich, there seem to be two conflated issues being cross-threaded in all these discussions.
An identifier that is simply globally unique - that is, the id is never duplicated and always refers to the same thing. So, you can use it as a unique reference in a paper, like an ISBN/ISSN number. But more importantly, it also can be used in data files/serialized XML to enable computers to quickly compare import/export records for merge/update, which is an important function to many, many biodiversity data projects. But, this id does not itself tell you where it can be found. Its location must come from another source.
An identifier that is globally locatable via the Internet - that is, the id is never duplicated and always locates the same thing (with a further definition needed of what the thing is). The globally locatable identifier needs to be locatable by a web browser (HTTP) but more importantly also by web services which may want to use a different protocol.
1 can be included in 2 as Nick has demonstrated.
I think we need some standard use cases against which we could test the options. I'm afraid this discussion in the abstract will be endless.
Do we have clear use cases for the biodiversity data GUIDs?
How well do relocatable identifiers work in the use cases involving the exchange/compare/import/export of millions of records from multiple sources?
Chuck