On an ideal Web, pages would stay put and links would never change. Of course, anyone who has been on the Internet long enough knows just how far away this ideal is. Commercial sites go out of business, personal sites move from school to school to ISP to ISP, news articles get moved into archives or deleted, and so on.
There are two sides to fighting link rot. The first is to design your own site with URLs that make sense, that you won’t find yourself changing a few months or years down the road. If you have to move something, use a redirect code so that people and spiders will automatically reach the new location.
The other side to the fight is periodically checking all the links on your site to make sure they still go where you expect.
So how do you handle online journals? Obviously they’re websites, so from that standpoint you should at least try to keep the links current. But on the blogging side, there are problems with this, in particular the school of thought that you should never revise a blog entry (also discussed in Weblog Ethics).
I’d argue that going back and updating a link in your own journal is like going back and fixing a typo. You hardly need to add a note saying, “Update: Changed the word “speling” to “spelling” in paragraph 3.” Since the upgrade to WordPress 1.0 I’ve done this here, silently updating both local and remote links in our actual posts. In one case I made a note because Symantec had not just moved an entry in its virus database, but renamed the virus as well.
But what if the page you’re linking to hasn’t just moved? What if it’s just plain gone? If you want to help keep the web’s signal-to-noise ratio high (well, keep it from sinking further into the muck), you should remove the link. But if you want to keep posts in their original state – for instance, to indicate that you had a source at the time – you should leave the link in.
Similarly, you have to deal with other people’s comments somehow. Simply changing them runs into problems, because you’re altering their words. The best thing may be to treat comments as letters to the editor – with you as the editor.
My inclination at this point is to (1) silently update links that have moved, (2) remove dead links but leave an inline comment like “[Note: CNN deleted the story],” and (3) update or remove links in comments with an inline note, making it clear that you changed the link and why. But I’m open to suggestions.
Sometimes, but not always, it’s possible to dig up a copy of a vanished page on the wayback machine. I generally find that linking an archived version is preferable to just saying “dead link!”, though of course you should mark the fact that it’s no longer live. (Ethics? Bah!)