Tuesday, November 17, 2009
Memento and Persistence
Following a long conversation with a coworker, I wrote down some thoughts about persistent identification schemes (including ARK, DOI, Handle, PURL). I had the post in the can, ready to go, when it was rudely interrupted by a really interesting presentation, which completely changed my thinking. I should recap that ill-fated blog post in one sentence before moving on: adding a layer of identifiers doesn't make an existing identifier more persistent, it makes it less so.
Now, that being said, there's a real problem. If I want to point at something as it exists on a certain date, it's often quite unwieldy to do so. Maybe I can cache it locally, maybe I can use one of the persistent identifiers mentioned in that first paragraph, or maybe I'm just out of luck. I point to someone's Geocities site, and it's just fricken gone. You see, the problem isn't that information moves to a different location, it's that the information at a given location changes. Or that it disappears entirely. That's a use case I care about.
Enter Memento. Herbert Van de Sompel and Michael Nelson gave a presentation about it at the Library of Congress yesterday, and I'm convinced it's a better way to think about persistence. Basic gist is that you specify a date with a URI, and a combination of clients, servers, proxies, and services try to give you back the thing you were pointing at, rather than the thing that's there now. I don't love all their terminology or even their implementations, but those are details. Memento is still a work in progress, and I like the approach.
Now, that being said, there's a real problem. If I want to point at something as it exists on a certain date, it's often quite unwieldy to do so. Maybe I can cache it locally, maybe I can use one of the persistent identifiers mentioned in that first paragraph, or maybe I'm just out of luck. I point to someone's Geocities site, and it's just fricken gone. You see, the problem isn't that information moves to a different location, it's that the information at a given location changes. Or that it disappears entirely. That's a use case I care about.
Enter Memento. Herbert Van de Sompel and Michael Nelson gave a presentation about it at the Library of Congress yesterday, and I'm convinced it's a better way to think about persistence. Basic gist is that you specify a date with a URI, and a combination of clients, servers, proxies, and services try to give you back the thing you were pointing at, rather than the thing that's there now. I don't love all their terminology or even their implementations, but those are details. Memento is still a work in progress, and I like the approach.
// posted by David @ 4:00 PM 
Subscribe to Posts [Atom]