Tim O'Reilly's Twitter feed pointed me at this great piece on historiography.
I just love the 12 volume set of the evolution of a single Wikipedia entry. In KLISS we take a very historiographic approach to eDemocracy.
The primary difference in the way we do it to the Wikipedia model is that we record each change - delta - as a delta against the entire repository of content : not just against the record modified. Put another way, we don't version documents. We version repositories of documents.
In legislative systems, this is very important because of the dense inter-linkages between chunks of content. To fully preserve history in the context of its creation, you need to make sure that all references are "point-in-time" too. I.e. if you jump back into the history of some asset X and it references asset Y, you need to able to follow the link to Y and see what it looked at *at the same point in history*.
Obviously, this is only practical for repositories with plausible ACID semantics. I.e. each modification is a transaction. It would be great if the universe was structured in a way that allowed transaction boundaries for the Web as a whole but of course, that is not the way the Universe is at all :-) - And I'm not for a minute suggesting we should even try!
Having said that, versioning repositories is a darned sight more useful than versioning documents in many problem domains : certainly law and thus eDemocracy which is my primary interest i.e. facilitating access, transparency, legislative intent, e-Discovery, forensic accounting and the like.
The fact that supporting these functions entails a fantastic historical record - a record that future historians will likely make great use of - is, um, a happy accident of ths history we are currently writing.