Archives of Sexual Behavior, Vol. 32, No. 1, February 2003, pp. 3–5 ( C  2003) Editorial The Numbers Game: The Impact Factor and All That Jazz Kenneth J. Zucker, Ph.D., 1,3 and James M. Cantor, Ph.D. 2 During the Editor’s undergraduate days in psychol- ogy (1968–72), he developed a love (perhaps even a para- philia) for the scientific journals. During his prolonged tenure as a graduate student, he spent countless hours in the stacks, rummaging around, reading too many jour- nal articles. By the mid-1970s, he had discovered Current Contents (CC), published by the Institute of Sci- entific Information (ISI). In the old days, prior to the era of the microcomputer and, later, the world of the Inter- net, he faithfully browsed through the weekly hard-copy issues of both the Social and Behavioral Science and Life Science editions of CC. With reprint request cards in hand, he must have asked for 10,000 articles during those years. Once it became possible to do this on the computer, with laser-label reprint request cards, it has been even more enjoyable to engage in this collector’s obsession. The Editor recalls once telling a version of this tale to a prominent contemporary sexologist, who replied “I never respond to reprint requests.” The Editor then said “Well, if you don’t reply, nobody will ever cite you.” He has responded faithfully to such requests ever since. The founder of ISI, Eugene Garfield, has done much more than establish the preeminent database of scientific periodicals. He has also written extensively on the science of scientometrics. This is a specialty area in its own right and beyond the scope of this editorial. Indeed, there is even a journal, Scientometrics, that is devoted to the topic (see Schubert, 2002). Garfield is particularly known for the establishment of the impact factor (IF) or citation analysis, which is deemed by many to be a reasonable index of a journal’s success and importance (e.g., Garfield, 1955, 1 Editor, Archives of Sexual Behavior. 2 Law and Mental Health Program, Centre for Addiction and Mental Health, Toronto, Ontario. 3 To whom correspondence should be addressed at Child and Adolescent Gender Identity Clinic, Child Psychiatry Program, Centre for Addiction and Mental Health – Clarke Division, 250 College St., Toronto, Ontario, Canada M5T 1R8; e-mail: ken zucker@camh.net. 1963, 1972; Garfield & Welljams-Dorof, 1992; Haynes, 1983; Rushton & Roediger, 1978), and a recent volume has honored this work (Cronin & Atkins, 2000). Although there has long been debate about the validity of the IF (e.g., Boor, 1982), there is nothing more heart-warming than to hear a colleague call out, after a few drinks in a darkened bar in the middle of a scientific meeting, “What’s the impact factor?” The current operational definition of the IF used by ISI is as follows: A journal’s IF for a given year is a mea- sure of the frequency with which its recent articles are cited on average during that year. “Recent” refers to the two prior calendar years. Thus, a journal’s IF for a year is calculated as the total number of times articles from the journal are cited over the two prior years, divided by the total number of articles that the journal published dur- ing those two years. For example, to calculate the IF for Journal X for 2001, one would count the number of times articles from Journal X were cited in 1999 and 2000 and divide it by the number of articles that Journal X published in 1999 and 2000. Although the IF is the best known metric for citation analysis, there are other measures, including the Immedi- acy Index (II) and the Cited Half-Life (CHL). The II is a measure of how frequently the journal’s “average article” is cited the same year in which it is published. Thus, the II for a year is calculated as the number of times articles from that journal are cited during that year, divided by the number of articles that journal published that year. The CHL is a measure of the longevity of the frequency of citations to the journal, that is, for how long the average article maintains its currency. The CHL for a year is deter- mined by the number of prior publication years required to account for a cumulative total of 50% of that year’s citations to the journal. When Archives of Sexual Behavior first began pub- lishing in 1971, there were really only two other scien- tific periodicals that were specialty journals in the sex and gender arena: Journal of Sex Research and Hormones and Behavior (and the latter publishes mainly on non-human 3 0004-0002/03/0200-0003/0 C  2003 Plenum Publishing Corporation