Will humankind be able to build on knowledge of today in 400 years? Will they be able to find older references. It is already difficult. Do we really believe in “perpetual access?”
As a STM reference librarian, I have been asked to find this article – often.
Citation: Briers, J. D. (1993). Holographic, speckle and moiré techniques in optical metrology. Progress in quantum electronics, 17(3), 167-233.
Working with researchers, I get to study their habits. I notice that even the most brilliant faculty and students have trouble finding older articles in STM fields.
In days of yore, they would go to the library stacks and take down the correct dusty volume by journal title, and be able to find an item 20 years old – or older.
Today, they may have a citation from a paper and be able to find the article through searching algorithms, but cannot get to the actual article. Reasons for this lack of access are many ranging from the expense of the access, to a bad citation, or a bad link known as “link rot.”
This article describes “link decoration” – a new term to me – to address “permanent access” to knowledge.
By Martin Klein and Herbert Van de Sompel (Please see the original article for linked access in this blockquote.)
Link decoration is a way to address these problems and to increase the chances that links will lead to meaningful content, even a long time after they were put in place. In order to maximize link robustness, the following information should be available, in a machine-actionable manner, for a link:
the URI of the snapshot, in our example https://archive.today/r7cov
the URI of the original resource, in our example http://www.w3.org/
the datetime of linking, in our example January 21 2015.
The latter two information elements can be used to automatically find snapshots in other web archives in case archive.today‘s service is interrupted, and the snapshot https://archive.today/r7cov becomes inaccessible as a result.
Discussions with interested parties are still underway regarding the best way to convey this information on a link. Until further notice, and for demonstrations purposes, the information is conveyed using HTML5’s attribute extensibility mechanism. Using that approach, this robust link to the W3C home page looks as follows:
data-versiondate=”2015-01-21?>this robust link to the W3C home page</a>
The Memento Time Travel extension for Chrome makes these link decorations accessible when right-clicking on the link. Try it with a version of the reference list of our above mentioned article in which links to web at large resource were decorated. For more information on link decoration, check out the Robust Links site.
For more on “link rot” please see a Georgetown symposium keynote by Jonathan Zittrain from Harvard Law School titled: Preserving our Digital Trail: A Call to Arms