Dr. Glowniak [1] presents a somewhat toneddown view of the Internet compared with that expressed in an earlier article in which he stated "The Internet has evolved ... to an information resource from which nearly all physicians can benefit. The medical applications on the Internet have become an unparalleled information resource that can be of great value to researchers, educators, and clinicians" [2]. The message in his Annals article is that "computer networks in general and the Internet in particular are likely to play more important roles in many aspects of medicine in the future." However, many challenges must be addressed before the Internet achieves its potential as a truly rich informational resource for practicing physicians. Although it has been shown that the amount of clinically useful information available electronically remains lacking [3], an increasing amount of information is becoming available on the Internet.

Finding relevant information on the Internet with a reasonable search sensitivity and specificity, however, does require some Internet familiarity. Internet search engines may only index data from a particular format such as gopher or the World Wide Web. The index terms may be taken from the document title, the source, the entire text, or keywords not necessarily drawn from any standardized medical terminology. Available search engines do not enable users to determine the quality or reliability of the resources found.

These issues are being actively pursued. Patrick and Springer [4] have described a scheme for classify biomedical Internet servers based on Medical Subject Headings (MeSH). The Unified Medical Language System of the National Library of Medicine provides a way to translate among the various medical terminologies used to index information. Its Information Sources Map categorizes information sources by content, intended audience, subject coverage, and other categories [5]. In 1986, the National Library of Medicine envisioned a mechanism whereby providers could transparently access vast quantities of clinically relevant information. Although today's Internet is providing the electronic highway, many street signs remain under construction.