I thought this comment by Karen Coyle points to a significant problem, particularly in a distributed environment.
"There is no logical connection between the Manifestation and any other WEMI entity. And it doesn't stand alone. Yes, I could add some identifiers, but they aren't inherent in the data itself so they would have to be artificial and not easily sharable."
I am not sure any of the WEMI entities have inherent identifiers. Perhaps barcodes on items are the closest thing.
It seems to me that Work records will only really be useful if they are a public good and available to everyone. Although Works don't really have inherent identifiers, theoretically, Work records could more easily have identifiers in the way that authority records do now. It may be that different groups will create different Work records which may have to be linked in some way, as the VIAF tries to do now for names. It may also be that people modify them for local versions, but they would presumably still link back to the public master identifier. More problematically, different groups may use different Work boundaries (when is something a new Work?), but possibly with more sophisticated linking, this could be handled. It won't be perfect (as authority records aren't now), but is hard to see how Work records would be truly effective on a large scale otherwise.
Expressions may be able to be handled the same way.
On the other hand, Manifestations, as Karen points out, have no inherent identifier and developing an environment where only a single record is consistently created for a single Manifestation remains a nontrivial, unsolved problem. OCLC is continually merging records or not merging those that don't have enough info to say what they are.
Manifestations often do have numbers, such as LCCN, ISBN, publisher numbers, etc., but these cannot be counted on to be unique. Some records have no numbers, except perhaps a local one. Some records consist entirely of information supplied by a cataloger so it is very hard to see how they could be reliably linked up with equivalent Manifestations (or even works).
OCLC numbers are the closest things we have to Manifestation identifiers. They are unique, but they aren't necessarily equivalent to a single Manifestation. Duplicate records are rampant. Sometimes the same manifestation is cataloged in different ways (e.g., individually and as part of a set). Not everything has an OCLC number, although there would be good coverage of mainstream materials.
So I am not sure how we could control Manifestations on a massive scale, especially in a distributed model rather than a centralized one. The best I could come up with is finding a way to say in a Manifestation record that this is a Manifestation record and then putting the Work identifier in the Manifestation record to say that this represents a Manifestation of or includes this Work. This does not completely resolve the problem as it would seem to be hard to manipulate the Manifestations if they don't have their own identifiers.
Or perhaps we could create a centralized repository of Manifestations and records could be linked to that. Which is essentially what OCLC is trying to do now, but definitely not in a way that those numbers will become a public good.
Or perhaps I'm just looking at this wrong?
Kelley McGrath
kmcgrath_at_bsu.edu
Received on Mon Oct 26 2009 - 14:38:19 EDT