Perhaps the most serious problem encountered during the development of these courses has been Link Rot, the disappearance of Web links -- URLs becoming incorrect. If a link fails for more than 24 hours, it may be broken.

It always is best to use original links. In many cases we have received permission to make copies of materials, however. When we have, the word 'local' will appear next to a link. Clicking the word local should bring you to our copy of the materials. The copied materials are not maintained, and will not work as well as the originals. They may be out of date.