A motley crew of folks had a chat via Google Hangout earlier this week to talk about FRBR and Fedora. I know exactly squat about Fedora, but I've just spent 18 months studying FRBR and other bibliographic models, so I joined the discussion. We came to a kind of nodding agreement, that I will try to express here, but one that requires us to do some hard work if we are to make it something we can work with.
The primary conclusion was that the models of FRBR and BIBFRAME, with their separation of bibliographic information into distinct entities, are too inflexible for general use. There are simply too many situations in which either the nature of the materials or the available metadata simply does not fit into the entity boundaries defined in those models. This is not news -- since the publication of FRBR in 1998 there are have numerous articles pointing out the need for modifications of FRBR for different materials (music, archival materials, serials, and others). The report of the audio-visual community to BIBFRAME said the same. Similar criticisms have been aimed at recent generations of cataloging rules, whose goal is to provide uniformity in bibliographic description across all media types. The differences in treatment that are needed by the various communities are not mutually compatible, which means that a single model is not going to work over the vast landscape that is "cultural heritage materials."
At the same time, folks in this week's informal discussion were able to readily cite use cases in which they would want to identify a group of metadata statements that would define a particular aspect of the data, such as a work or an item. The trick, therefore, is to find a sweet spot between the need for useful semantics and the need for flexibility within the heterogeneous cultural heritage collections that could benefit from sharing and linking their data amongst them.
One immediate thought is: let's define a core! (OK, it's been done, but maybe that's a different core.) The problem with this idea is that there are NO descriptive elements that will be useful for all materials. Title? (seems obvious) -- but there are many materials in museums and archives that have no title, from untitled art works, to museum pieces ("Greek vase",) to materials in archives ("Letter from John to Mary"). Although these are often given names of a sort, none have titles that function to identify them in any meaningful way. Creators? From anonymous writings to those Greek vases, not to mention the dinosaur bones and geodes in a science museum, many things don't have identifiable creators. Subjects? Well, if you mean this to be "topic" then again, not everything has a topic; think "abstract art" and again those geodes. Most things have a genre or a type but standardizing on those alone would hardly reap great benefits in data sharing.
The upshot, at least the conclusion that I reach, is that there are no universals. At best there is some overlap between (A & B) and then between (B & C), etc. What the informal group that met this week concluded is that there is some value in standardizing among like data types, simply to make the job of developers easier. The main requirement overall, though, is to have a standard way to share ones metadata choices, not unlike an XML schema, but for the RDF world. Something that others can refer to or, even better, use directly in processing data you provide.
Note that none of the above means throwing over FRBR, BIBFRAME, or RDA entirely. Each has defined some data elements that will be useful, and it is always better to re-use than to re-invent. But the attempts to use these vocabularies to fix a single view of bibliographic data is simply not going to work in a world as varied as the one we live in. We limit ourselves greatly if we reject data that does not conform to a single definition rather than making use of connections between close but not identical data communities.
There's no solution being offered at this time, but identifying the target is a good first step.