Credits and IVOA Identifiers in SSA0.97

[Alberto Micol]

On Dec 18, 2006, at 16:35, Doug Tody wrote:
>
> Probably STECF is the Creator of this data collection.  You should
> define registry entries for Creator and Collection, and each spectrum
> should have a unique CreatorDID within the collection.  If we then
> replicate the collection at MAST and CADC, those are Publishers
> and have their own PublisherDID for each dataset, with Creator
> and CreatorDID unchanged.

I like the fact that CreatorDID remains the original one. That makes  
possible
to compare two products from different publishers, and see whether  
they are
actually the same product or not.

And, I guess, also the DataID.Collection should remain untouched in  
that case.
It will be via the DataID.Collection that a user could look up into  
the registry
to see whether the same collection can be retrieved from a different  
publisher
(e.g. when there is a network problem, etc). The problem though is that
the Collection as defined in 3.3.3.11 is not necessarily unique, it  
is not
a ivoa identifier.


About Credits:

How to give credits in general?
In particular: there might be cases where a second creator/publisher  
changes
(slightly or heavily) the products originated by the first creator.
In that case Creator, CreatorDID, Publisher and PublisherDID will all be
related to the second creator, and information about the first one  
gets lost.
How to give credit to the first Creator?

Last question:

DataID.Creator is a recommended field and
Curation.Publisher is a mandatory fields.

Those are short strings, not at all guaranteed to be unique.
Why not mandating the usage of the CreatorID and PublisherID
being them ivo identifiers? Important to look them up into the  
registry...


Thanks,
Alberto