Scholars cite their sources of information for three main reasons: 1) to insure that the information conveyed is accurate, 2) to guarantee their readers access to the full context in which the material was cited, and 3) to credit authors) (“intellectual honesty”). In short, the essence of citation is verification of information.
“Here Today and Gone Tomorrow,” or Dead URLs and Links
Clearly, neither intellectual honesty nor accuracy can be verified if the source consulted is no longer available. The reader cannot analyze the researcher's use and interpretation of the evidence. Frequently, only months or even weeks (sic!) after publishing, an electronic document gets deleted from a university server. Internet addresses (so-called “URL” - Uniform Resource Locator) are often changed by Webmasters or system administrators for technical purposes, and Web sites may disappear without any trace from cyberspace, due, for example to lack of sponsors. Repeatedly, electronic messages are moved after a certain period of time and stored in the administrator's archives, which are not generally accessible to the public. This is true especially of list-servers' messages or newsgroup postings.
Unfortunately, this phenomena is not a sporadic one. When the author of this paper checked ARS MEDICI, a collection of 20,000 medical Internet addresses published on a CD-ROM in 1997, it turned out that over 50% of all addresses were dead links.5
Can we imagine any scientific paper citing references of which less than 18 months later only 50% are available? A bibliographical disaster!
“Invisible Changes,” or New Contents and Old URLs
Another example: What if someone (computer system manager, Web site author or hacker) modifies a document AFTER a surfer has cited a particular electronic document? For example, the author of a Web site on endoscopy presents some facts on the history of that procedure under URL: www.example-endoscopy.com/history.html
. There, a surfer may learn that the first surgeon who performed laparoscopic cholecystectomy (LC) was Phillipe Mouret of Lyon, France, in 1987. Some time later, however, the author of the site discovers that it was E. Mühe of Böblingen, Germany, who had carried out the first LC in 1985, and not the aforementioned French surgeon. Consequently, the author alters the contents of the Web site because of this “new” information but not its address (URL) -- a common routine in Cyberspace known as “updating.” Now, it is possible to have two groups of researchers pointing to the above-mentioned Web site: one group, who picked up the historical information before the site was updated (“Phillipe Mouret was the first”), and the other group, who reached the Web site after it was updated (“Erich Mühe was the first”). As a result, we are confronted with an unacceptable situation -- both groups would quote the same reference (Internet address), but both would refer to totally different facts.
Citing and the Topic of (not only Scientific) Responsibility
The situation might conceivably become more problematic (or even dramatic) if this phenomena occurs on Web sites dealing with clinical issues, for example, application of drugs, interpretation of labor findings, or recommendation of certain operation techniques. The law dealing with information obtained from or through the Web is not well defined. Potential legal issues include responsibility for diagnostic and therapeutic procedures based on Internet information.
Equally troublesome is the question of interaction between physicians and patients over the Internet, when, for example, it may occur that a physician practices medicine without being licensed in the state or country in which the patient resides.
Clearly, there is no foolproof mechanism to prevent erroneous information from being placed in print media, but with printed material there are effective methods to store the information. Indeed, in the case of print media, we can reach the source directly at any time through any number of means, such as interlibrary loans. Due to well developed library systems, it is not a problem to reach, for example, the works of Theodor Billroth (1829-1894), William S. Halsted (1852-1922), or Rudolf Virchow (1821-1902), written more than 100 years ago. In the case of electronic sources, we do not have such a system.