Link rot limits the usefulness of web-based educational materials in biochemistry and molecular biology

The differential stability of biochemistry and molecular biology Web page resources based on their domain designation is described. Many teachers have been excited by the potential enrichment of placing hyperlinks to Internet distributed educational resources within the class materials available to their students. However, there seems to be a belated realization that such hyperlinked resources are not necessarily stable and often disappear, causing frustration for both instructor and students. We recently developed three graduate-level biochemistry and molecular biology courses for distance delivery to high school teachers that relied heavily on such Web-based distributed resources. The 515 hyperlinked Web pages in these courses represent a set of authentic science education resources that were monitored for 24 months since their creation (August 2000). During this time, over 20% of the URLs have been victims of "link rot," becoming nonviable, moving without automatic forwarding, or having their content changed.