GREAT MINDS THINK (TOO MUCH) ALIKE

July 28, 2008
The Financial Express

Online databases of scientific journals have made life easier for scientists, as well as publishers. No more ambling down to the library, searching through the musty stacks and queuing up for the photocopier. Instead, a few clicks of a mouse can bring forth the desired papers and maybe others that the reader did not know of—the ‘long tail’ of information that the web makes available.

Well, that is how it is supposed to work, but does it? James Evans, a sociologist at the University of Chicago, decided to investigate. His conclusion, published recently in Science, is that the opposite is happening. He has found that as more journals become available online; fewer articles are being cited in the reference lists of the research papers published within them. Moreover, those articles that do get a mention tend to have been recently published themselves. Far from growing longer, the long tail is being docked.

Evans based his analysis on data from citation indexes compiled by Thomson Scientific (part of Thomson Reuters). In a world in which researchers must publish or perish, such indexes are the firing squads. They record how often one article is cited as a source by others, and thus measure a paper’s influence. Those used by Evans cover 6,000 of the most prominent academic journals, some going back to 1945.

By cross-referring these to a database called Fulltext Sources Online, he was able to work out when each of these journals became available on the web—and whether a journal had posted back-issues electronically as well. The result was a set of 34 million research papers, which he was able to mine in search of his answers.

For each research paper he looked at, Evans calculated the average age of the articles cited as references. He then calculated, for each of those cited articles, the number of back-issues of the journal it had been published in which were available on the web at the time when it was cited, and averaged that too. Finally, he looked for correlations between the two averages.