Bibliometric ups and downs

Abstract

Bibliometrics is the science that, among other issues regarding books, articles and other publications, analyzes the performance of scientific journals. The Impact Factor (IF) is the most popular measure of the influence of a journal, and its size is usually used to rank tribunes. If the IF is large, the journal is good. Just as with the hopes of economists, with GDP and other economical paraphernalia, the expectation is that the IF grows every year, and we editors anxiously wait for the publication of the IF by the Institute for Scientific Information. This year our IF decreased a little bit, from 0.865 to 0.761. As Editor-in-Chief, I should commit hara-kiri! Another metric, however, savedmy life. It is the Cited Half-Life (CHL). Never heard about it? The IF measures how much the articles are cited three or five years after publication. The CHL measures for how long the articles keep being cited. I am proud to tell you that the CHL of the Italian Journal of Zoology reached >10 this year. We never had such result. This is the top value of this measure: it means infinity. So, our articles are now more or less immortal. Maybe they will not be cited much soon after publication, but they will not disappear from the radar of those who study zoology, according to this bibliometric measure. What is more important? The IF or the CHL? The answer is clear: the IF. Nobody cares about the CHL, so why bother? I suggest a little study. Inspect the rankings of the journals in the various disciplines and order them according to either IF or CHL. You will be surprised. Usually, the larger the IF the smaller the CHL, and vice versa. The papers that appear in highly impacting journals, with due exceptions, are rapidly forgotten. They are worth gold as soon as they are out, but their value decays very rapidly. The reason is that there are ‘rapidly evolving’ disciplines, and there are others that evolved already. In this case, rapidly evolving might be expressed also with ‘rapidly decaying’ disciplines, since their highly impacting articles are soon forgotten. Our problem is not the IF – those who have it large are right in praising their size – but we should not be ashamed by our size, we have other resources to counterbalance this poor measure. Our problem is that we are not even aware that CHL exists, and this leads to inferiority complexes in respect to other disciplines. They have such a large IF, and ours is so tiny! Maybe it might be wise to merge these two values and find a cumulative index that considers both aspects. Something like IF × CHL. But if you multiply a tiny number for infinity (CHL >10 is infinity) you have infinity. Whereas if you multiply a huge number for a number that is not infinity, the cumulative index is lower than infinity. I fear that the guys who practice disciplines with tiny CHL would not like this measure. That’s why they do not care about CHL. As usual, the fault is ours: we should care about CHL much more than about the IF. We developed an inferiority complex generated by the size of our IF, and did not realize that, in those bibliometric columns, there is also the CHL. And that our scores are not so bad, as a whole discipline. Now it is our duty to defend our reputation and keep asking that the CHL is considered together with the IF. The publishers, in the web pages of the journals, report only about the IF. They should report also the CHL values. We have evolved already, and we have a solid background on which to base our research. There will be exciting novelties also in zoology, of course, but they will probably be less triumphant than those of other disciplines. They will, however, last for much longer a time. Be proud to be a zoologist!