Broken Links: The Ephemeral Nature of Educational WWW Hyperlinks

The use of distributed (Internet) resources to enhance both traditional and distance education has caused much excitement in the science education community. However, one of the difficulties with relying on such freely available distributed resources has been the lack of certainty that the resources will be available for students next month, next semester, or next year. We have recently been involved in the development of three graduate-level biochemistry courses designed for high school teachers. Development of these courses relied heavily upon distributed science education resources. As a consequence, they represented a set of authentic science education resources that could be monitored over time to determine their rate of extinction. In total, the three courses contained 515 nonredundant URLs representing either scientific content of science education pedagogy. These have been monitored on a monthly basis during the 14 months since the creation of the courses (August 2000). During this period 85 (16.5%) of the URLs have ceased to function or had their content changed. The most attrition was seen in URLs with the "edu," "com," and "org" domain names, in which 17.5, 16.4, and 11% have already become inaccessible.