Online today, gone tomorrow.

• Author: Swartz, Nikki
• Position: Up front: news, trends & analysis - Researchers relying on online sources for information

By the time a research report or publication goes to press, many of its references, in the form of footnotes and endnotes, may no longer exist. That is because more researchers and professionals are relying on information found oil Web sites as sources for their scientific, academic, and white papers.

Today, references are more likely to refer to Web pages than books or journal articles, hut before the ink dries, many of the sites cited will have moved to other locations on the Internet or disappear altogether, rendering them useless to readers.

In research described in a recent edition of Science, a team looked at footnotes from scientific articles in three major journals--The New England Journal of Medicine, Science, and Nature--three months, 15 months, and 27 months after publication. The prevalence of inactive Internet references grew during those intervals from 3.8 percent to 10 percent to 13 percent, respectively.

People are increasingly dependent on the Internet to get information from companies, organizations, and governments. Yet, studies have revealed that the average lifespan of a Web page today is a mere 100 days. For example, of the almost 2,500 British government Web sites, 25 percent change their uniform resource locators (URLs) each year, according to Electronic Publishing Services in London.

A growing number of scientists and scholars are nervous about the...