I was very struck a couple of years ago by a comment made by my colleague Eric Hellman. He talked about metadata in terms of rivers and lakes. In the library cataloging model we have had lakes - accumulating stores of data that do not change frequently over time and are fed by a few principal sources. In the ERM/Knowledge Base model we have rivers - stores of data that change frequently as products and services change and which are fed by many streams.
And as Heraclitus is reported to have said: you cannot step into the same river twice. The data river for licensed materials is always in flux.
Now, I think that we will need to get used to cataloging data becoming more river-like also, more in flux, as that environment too becomes more dynamic. Here are some examples ....
- Work based approaches. We are getting used to thinking about clustering records as works. Works are dynamic: new manifestations or expressions may continue to appear and be linked in various ways to the work or expression to which they belong. If we move to represent the other FRBR entities in appropriate ways, we may link bibliographic data to data about subjects, names and so on.
- We have a similar relationship issue as materials are digitized and may live in different places. How do we represent the relationships between items and digitised versions of them.
- Rights data has become more important as we want to do more with books than buy them and make them available physically to a local audience. In particular, digitization has caused us to ask questions about what can be done with the book content. This has caused us to look at data in new ways and to think about what data is needed. (See the newly released Worldcat Copyright Evidence Registry, for example.)
- We are becoming used to collecting data from users - tags, ratings, reviews, additional details, ... - about materials in an ongoing way.
Update: I changed the order of the Heraclitus sentence this morning and then noticed that Roy had quoted the earlier version in a nice amplification of the river theme. I do sometimes wonder about the etiquette of changing stuff, but usually only note big changes.