Durable Links from Paper to the Web

by Bob DuCharme

Related link: http://free-culture.cc/notes/

It's difficult to write about technology, particularly the web, without mentioning URIs. Cool URIs don't change, but many uncool URIs are still useful. This presents a problem when writing something for distribution in a book, magazine, or other hardcopy format—if a resource's URI does change, you can't update your reference to it.

While reading the Penguin Press edition of Lawrence Lessig's book Free Culture, I saw the URI www.webstationone.com/fecha in the first footnote and wondered how robust it was. The full footnote reads

See "Saints: The Heroes and Geniuses of the Electronic Era," First Electronic Church of America, at www.webstationone.com/fecha, available at link #1.

I saw that the introduction to the Notes section says "For each link below, you can go to http://free-culture.cc/notes/ and locate the original source by clicking on the number after the # sign. If the original link remains alive, you will be redirected to that link. If the original link has disappeared, you will be redirected to an appropriate reference for the material." I checked that web page and saw that the URI for link #1 had already changed. The Notes page also includes the e-mail address of someone that readers can alert about broken links on the page.

This approach reminds me of the old computer science aphorism (50 years old, apparently) "Any problem in computer science can be solved with another layer of indirection." It was nice to see how this principle fixed such an apparently low-tech problem.

"Free Culture" is a great book, by the way, and worth reading if your vocation or avocation involve content that can be considered intellectual property. Lessig's description of the historical British and then U.S. legal treatment of intellectual property (as opposed to physical property, and much turns on the distinction) provides a solid background for anyone interested in discussing the issues intelligently. In my experience, those who claim to disagree with Lessig usually disagree with exaggerated second-hand reports of his opinions; they should try the primary source. Free versions of the book are available at the website, but the bound version is more convenient to read. I've recommended to several friends that they read the first chapter or two of the free version to decide whether to buy the book.

Indirect linking from paper to the web must be older than "Free Culture"; who did it before Lessig?


2004-07-08 17:54:04
the 2nd part of that aphorism
", except too many layers of indirection".
2004-07-08 21:49:08
We need more of this
I wish that more authors would use this kind of stratagy. I have a number of books around here (many from O'Reilly) that have just that problem. The have pointers to great but stale links.

It should be noted that in order for this to work the author needs to take responcibility to maintain their work. This is often the case for computer literature because newer versions can be just as lucrative as the origional. I suspect that authors of others subjects of information would be less likely to maintain their document references in the same manner. Once they are finished and have received the royalties for a given book they are finished. (class text books might are probably an exception)

The other facter that needs to be considered is how much responcibility the publishers have to continue hosting sites for older books because they are most likely footing the bill bandwidth and storage that supports those complimentary web pages. Maybe somebody as knowledge or good anecdotal evidence as to just how long most publishers are inclined to do so?

2004-07-10 04:00:47
For durable links of all kinds, consider using Persistent Uniform Resource Locators, which you can register, for example, at http://purl.org/.

They have the advantage that even if the publisher's page gets lost, the references still can be updated to point to new pages, mirrors, or placeholders.

2004-07-13 06:34:16
Thanks. I keep bumping into interesting work being done at the OCLC and need to devote some time to more thorough research.