Your breakdown here is really helpful for me, but I have a question about your conception of how the library-controlled information is handled in BIBFRAME.

On May 23, 2013, at 12:12 PM, Jörg Prante <[log in to unmask]> wrote:

- extract all library-controlled information out of the FRBR classes - the formal description, the classification, the subject cataloging, the call number, the shelf location, authority control information, (maybe also descriptions of the library service for access to printed and electronic resources, it's not clear right now) etc. Put that also into bf:Instance.

I don't know that I would consider this Instance information under the BIBFRAME definition of Instance. A lot of it (call number, shelf location, library service) seems more like item information, and might be a library annotation. It's related to a specific library's copy of an Instance. 

I'm also still a little baffled about BIBFRAME's use of Work. I can't figure out whether it's closer to FRBR's concept of Work (conceptual essence) or Expression. Personally, I think something closer to Expression would be more important for libraries' goals, and the line seems very blurred to me, here. Are we describing a particular expression of a conceptual essence, or the concept/idea itself? Or both? I  suppose I will have to anxiously await the release of the Creative Work discussion paper. (Though your suggestion to go back to the Primer was a very useful one.)

Laura Krier
Metadata Analyst
California Digital Library