WireWise Making the Most of the Internet Peter Suber & Liffey Thorpe Issue #2. April 23, 1998.
When A Link DiesWhat do you do when a link dies? The link may be in your bookmark file, in a list of hits returned by a search engine, on a page you use as a reference, or on your own page. Don't despair. A dead link does not mean that the site has disappeared from cyberspace.
The two most common explanations for dead links are (1) that the computer hosting the page you seek is temporarily down and (2) that the page has moved to a new address. In the former case, the link will work again in a few hours or days. You would be wise to assume the latter, however. At least that way you will take some constructive steps while you wait to try the link again.
First, study the URL. Suppose it is
<http://www.stateuniversity.edu/physics/~hornblower/research.html> This tells you that the page you seek is located on the hard drive of a server of "stateuniversity" in the subdirectory devoted to physics, in the subdirectory of Prof. Hornblower. Hornblower might be a grad student, secretary, or alum, not a professor, but has permission to store files in the physics directory of stateuniversity.
The error message that told you the link is dead really only means that the file named at the end of the URL —research.html— cannot be found in the hornblower subdirectory of the physics subdirectory of the stateuniversity server. The file, perhaps with Hornblower, may have moved elsewhere. If they're still online, we can look for them.
Edit the URL by cutting off the file name. Now the URL ends with ".../~hornblower/". Leave the last slash in place. Now ask your browser to search for this truncated URL. If there is an "index.html" file in the hornblower subdirectory, your browser will now take you to it. Search the index page for a link to "research.html" or for some idea of how Prof. Hornblower might have reorganized his or her home page. If there's no "index.html" file in the hornblower subdirectory, you'll be given a list of files that are in that subdirectory. Pick one that looks like the name of the professor's home page and scan it for clues.
If the truncated URL is also dead, truncate again. This time you'll be looking for the index file for the Physics Department. If you find it, look for links to Hornblower. If the site lists all kinds of physics personnel but omits Hornblower, then perhaps Hornblower has moved on. If this URL is also dead, then stateuniversity has probably reorganized its site —without, of course, redirecting or even informing needy patrons like you. If so, when you truncate one more time, looking for the front page for stateuniversity. You'll almost certainly get a valid page. Use it to find the physics page, and use it to find the Hornblower page.
If this method doesn't work, turn to a search engine. Make a simple search for Hornblower or a boolean search for "hornblower and ..." where the second term is one of the key terms from the file you seek. Some of the hits will be links to the old URL that you know is dead. But some may help you find Hornblower's new lair.
Sometimes you'll find the Hornblower page but not the individual file you want. In that case, send Hornblower email. If you find the physics page but not the Hornblower page, send email to someone in physics asking where Hornblower went. This method works better when Hornblower's old domain is stateuniversity.edu than when it is globalmegabell.com.
In our experience, the "trunc 'n hunt" method works about 75% of the time. Search engines and email work most of the rest of the time. If none of the three methods works, the chances are good that the page really has gone offline. But even in that case, it might well reappear when Hornblower settles in at a new URL after leaving stateuniversity. If you spent the time to make some pages good enough for others to search for, and if you were —ahem— forced to move away from your original service provider, wouldn't you put them back online when you got back on your feet?
WireWise is an occasional newsletter of tips for academic users of the internet. We welcome your feedback, questions for us to answer, and topics for us to cover.