Rwp03: RSM changes

[Robert Hanisch]

Well, it took me about 2 hours just to read through the e-mail from the past
few days!  Nice to see people being busy!

This is mainly a response to Tony's suggestions about RSM v0.7.

I'd prefer to keep the "Service" in RSM.  While everything is a resource,
not all resources are services.  This also means retaining the separate
section 4 to emphasize that there are metadata specific to services.  I
think it is perfectly valid, and useful, to register resources that may not
be directly invokable as services.

Thus, the "organization" described in Section 2 is really just that, an
organization, and not necessarily a community service.

I had assumed that all metadata elements would be "filled in" for all
resources, and where a metadata element is not applicable a suitable default
or flag would be entered (perhaps by the interface supporting registering).
This seems to me a better approach than leaving things out.  For example,
setting Coverage.Spatial to the equivalent of "not applicable" carries more
information than omitting it entirely.  Just like we can validate VOTables,
we should be able to validate registry entries for completeness and
syntactical correctness.

I am not sure about Supported Metadata Formats.  In looking back over the
OAI stuff, it seems to me that OAI has these in order to deal with the
historical reality of different schemes of encoding basically the same
metadata elements.  But we should have no such problem, at least not at the
basic registry level.  I know most people now seem to agree that the UCDs
contained in resource or service should be included in the registry, but I
am not convinced of this. Perhaps SMFs could be a mechanism for handling
UCDs, but it just does not seem to me a necessary component of the registry.
This all seems to me to be requirements creep.

The issue of hierarchies is again the issue of depth, or granularity.  Is it
really a problem if a registry query returns with both MAST and HST?  Or
with both Vizier and a particular catalog in Vizier?  The associated
metadata will make it clear which is the more specific resource.  In
general, I think the registry should be quite unsophisticated about such
things, and leave it to applications that utilize the registry to pull out
and use what they want.

Cheers,
Bob