Directions:
Click on this link to locate the page about magic squares.
Note that the search engine is no longer able to find the page.
Whenever this happens, there are as many as three strategies you can try. Try all three, although you don't need them all to find the missing information.
Magic Squares
Strategy 1: Search the cache (or the referring database)
If you click on a page that the search engine just returned and get the "Page Cannot be Found" message, try looking at the cached version of the page. This should work if the page was recently removed by its owner. Databases like Google maintain a cache of the page they indexed that last time they visited the page.
That will not work in this case, because you didn't get the message because it was referred by a search engine.
You can try searching a database (e.g., Google) for specific information that you extract from the URL. For example, what do you find if you search for magicsquares.html and suzuki?
To verify you did this, post your finding in your JOURNAL.
Strategy 2: Search the site
If at first you don't succeed, you have something else you can try. Without leaving the site, you should check to see if the missing page was moved to another on the site by its owner or publisher.
This is a secondary or investigative searching technique that uses truncation. To truncate the url, remove the end of the URL back to the last / mark. In this case, that results in
http://www.pse.che.tohoku.ac.jp/~msuzuki/
which turns out to be the root directory for Mr. Suzuki's personal web space (indicated by the ~).
What message do you get when you enter Mr. Suzuki's root directory? Add this to your JOURNAL posting.
Truncate back to the next / mark. This opens the main site:
http://www.pse.che.tohoku.ac.jp/
Here is where you would search for the magic squares document in case it was moved to a new location on the site. However, there is no search box and the links do not lead to anything promising. Furthermore, there is no link to Mr. Suzuki among the faculty links.
Strategy 3: Search another database
Finally, there is a specialized database for just about every subject on the Internet, including an historical Archive of Web pages.
Go to http://www.archive.org/ and enter the complete URL of the missing page into the search box for the WayBackMachine. There you will find Magic Squares pages going back to 1997. Note the URL of the working copy of the Magic Squares page and that all the links work. (Archive.org not only saved Mr. Suzuki's page, it saved all the pages he linked to!)
You can also enter clues about the missing page into a Google search. Specific information is available about the author and the document. Try a query like suzuki MagicSquare.html to see if it may be indexed anywhere else in Google. If someone else thought it was a valuable resource, they may have copied it and preserved it in another database. Try it and see what you find!
For online Course participants: To verify that you did this, post in your JOURNAL the date of the earliest copy of Magic Squares (include the month and day). Also be sure to check out the latest copy which explains why the page is no longer available.