Dividing the Best From the Rest
An influential measurement uses a Moneyball approach to rank medical journals.
Medical researchers, like other writers, want to publish their work where it will have the best exposure. But how to distinguish among the many thousands of journals? Manuscript authors sometimes consult a metric called the Journal Impact Factor. JIF rankings are featured in a publication called Journal Citation Reports, a Thomson Reuters title issued annually since 1975 and available in most academic libraries. In 2012, JCR calculated JIFs for 10,699 journals published around the world.
“The impact factor reflects the quality of a journal through the very particular lens of scholarly citation,” says Marie McVeigh, director of JCR and Bibliographic Policy at Thomson Reuters. To determine a publication’s JIF, McVeigh’s team first scans the most recent completed year of the scientific literature—say, 2011—and counts the number of times that content from the prior two years of a particular journal has been cited as a source during those two years—in this case, 2009 and 2010. That total is divided by the number of scholarly works that appeared in that journal during the two-year period. Among general medical journals, The New England Journal of Medicine (53,298) had the top JIF for 2011.
Academic librarians also check JIF rankings to decide which journals to purchase. Critics, however, say this measurement can be misused—for example, when tenure and grant committees, strapped for time, look at the JIFs of journals where a scientist has published instead of reading the researcher’s papers. That could cause important work to be overlooked, says University of Manitoba cell biologist Grant Pierce. “It’s not the journal that determines the quality of a paper, it’s the paper,” says Pierce.
What’s more, editors have found ways to artificially inflate JIFs, such as by publishing review papers that reference every article appearing in their journals during the prior two years, a practice known as journal self-citation. Last year, JCR withheld the JIFs of 50 journals that it accused of “anomalous citation patterns.”