Patience Is A Virtue
Don’t be misled by citation figures! (21)
by Ralf Neumann, Labtimes 02/2010
Finally, Brevocchio had the data signed and sealed. “Send it to Ecology. It’s a good journal and your article would fit in well,” Clemente, his boss, advised.
But Brevocchio had doubts. Sure, Ecology was a renowned journal. It had, after all, been founded in 1920 by the Ecological Society of America. However, Brevocchio had always found it a bit dated. Really modern ecology, which in recent years increasingly included molecular methods and mathematical models to solve their questions, was only gradually making its way into Ecology. Yet, modern was exactly the style in which Brevocchio had completed his work.
No, in the meantime younger, more exciting journals had come out that were tackling these new trends in ecology head-on. Molecular Ecology, for example, Brevocchio’s favourite journal.
When, a few days later, he incidentally noticed that the impact factor ranked Mol Ecol (IF 5.3) just ahead of Ecology (IF 4.9), his line of action became completely clear to Brevocchio. All Clemente said was, “If you want to – okay, try it.”
Three months later, the paper was published in Mol Ecol. While Brevocchio was toasting the publication over a glass of champagne with Clemente, he was suddenly asked, “Why did you actually send the manuscript to Mol Ecol?”
“I just like Mol Ecol better than Ecology,” Brevocchio answered. “Besides, it has the higher impact factor.”
“And what do you think this tells you?” Clemente was curious.
“That more people quote the articles published in Mol Ecol – and, thus, read them, too?”
“That’s interesting,” Clemente replied, “I took a closer look at this issue just a few days ago – and I noticed that this probably isn’t quite true.”
“What do you mean ‘not true’?” asked Brevocchio, suddenly becoming nervous.
“Well, fact is, the impact factor only indicates how often all articles, published in one journal within two given years, have been cited during the subsequent calendar year,” explained Clemente. “However, that does not reveal how frequently a paper has been cited in total over all time. And the so-called ‘cited half-life’ of Mol Ecol, in fact ...”
“What’s that?” Brevocchio interrupted.
“It’s a measure of how long the articles of a certain journal are cited on average. More precisely, the ‘cited half-life’ denotes the number of previous years that account for 50% of the total citations received by a given journal in the current year.”
“And?” asked Brevocchio, becoming even more nervous.
“Ecology is a lot better in this respect,” Clemente went on to explain. “Ecology has a ‘cited half-life’ of about fifteen years, whereas Mol Ecol comes to only about five and a half. This means that, on average, an article in Ecology is quoted over a period almost three times longer than in Mol Ecol. And, since both their impact factors lie fairly close together, it’s very likely, in the long run, that an article in Ecology is actually cited more frequently in total.”
Brevocchio grimaced as if he had just been slapped around the face with a wet fish!
“Well, just for fun I randomly compared twenty 1995-papers from each of the two journals,” Clemente continued. “And indeed, on average, the Ecology articles have been cited twice as often to-date as those from Mol Ecol.”
Brevocchio flinched again, as if he had now swallowed the fish whole!
But Clemente patted him on the shoulder and said, “Don’t worry about it, old chap. Your article is good, actually very good. And these days, good articles will be read – and cited – wherever they appear.”
Last Changed: 03.05.2012