Showing posts from November, 2010

2010-11-15: Memento Presentation at UNC; Memento ID

I recently had a chance to return to the School of Information and Library Science , UNC Chapel Hill, where I had a most enjoyable post-doc during the academic year 2000-2001. Jane Greenberg was nice enough to invite me to speak about Memento in her INLS 520 "Organization of Information" class on Tuesday, November 9th as well as give an invited lecture about Memento to the UNC Scholarly Communications Working Group on Wednesday, November 10th. When I first went to UNC I had the office next to Jane and she was just an assistant professor, now she's a full professor and director of the Metadata Research Center . I enjoyed catching up with her and my many other friends and colleagues at SILS. My slides are available on ; they are mostly a combination of slides I've posted before, but with some updates in the HTTP headers. Although the changes are very slight, the recently submitted (11/12/10) Memento Internet Draft takes precedence over all of our

2010-11-05: Memento-Datetime is not Last-Modified

One of the key contributions of the Memento Framework is the HTTP response header " Memento-Datetime " (previously called "Content-Datetime" in our earlier publications & slides). Memento-Datetime is the sticky, intended datetime* for the representation returned when a URI is dereferenced. The presence of the Memento-Datetime HTTP response header is how the client realizes it has reached a Memento. Rather than formally explain what we mean by "sticky, intended datetime", it is easier to explain how it is neither the value in the HTTP response header Last-Modified , nor is it the creation date of the resource (which has no corresponding HTTP header, for reasons that will become clear). For the examples below, we'll define the following abbreviations: CD (Creation-Datetime) = the datetime the resource was created MD (Memento-Datetime) = the datetime the representation was observed on the web LM (Last-Modified) = the datetime the resource last cha