Temporal context is an important and much overlooked aspect of preservation. Users of preserved information need a way of using that information in its original context. Many born-digital documents are not isolated and complete in themselves, but are part of a network of documents. Providing temporal context means preserving the context of a document at the time it was created.
When we preserve a document (however we might define “document”), the links in that document to other documents should not only work, but should also link to the same content that the author linked to at the time the document was created — not to a later version that the author never saw that may have replaced the document the author linked to. (We might also want to link to the later or current versions, but we need to know when we want to do that and be able to give the user the information she needs to know what she is getting and the choice of what to get when there are choices.)
This relates both to versioning (identifying different versions and editions and modifications of documents) and also to link-rot (keeping links working and working properly).
Here are two readings and a podcast that address these issues.
- Ainsworth, Scott G. 2013. “Browsing and Recomposition Policies to Minimize Temporal Error When Utilizing Web Archives.” Bulletin of IEEE Technical Committee on Digital Libraries 9 (2).
- The Web’s Missing Dimension: Time, Jon Udell interviews Herbert Van de Sompel, Digital Librarian, Interviews with Innovators (April 14, 2010) [44 minutes mp3 file].
Herbert Van de Sompel is a digital librarian who wonders why the web has no memory, and wants to do something about that. In this conversation he tells host Jon Udell about the Memento project, a proposed protocol that browsers can use to scroll through historical versions of web resources.
- Memento: Time Travel for the Web. by Herbert Van de Sompel, Michael L. Nelson, Robert Sanderson, Lyudmila L. Balakireva, Scott Ainsworth, Harihar Shankar.