The journal impact factor (JIF) has long been used to assess a scientific journal’s impact on researchers and academics—but is it really the best way to measure this information? A group of researchers has developed an alternative metric based on citations originating only from citable items in the journal, sharing their findings in Academic Radiology.
The JIF is calculated by adding all citations from “citable and noncitable items” from a journal in a single year and then dividing it by the number of citable items in that journal from the previous two years.
“The citable or source items counted in the denominator of the JIF are identifiable in the Web of Science as ‘article,’ ‘review,’ and ‘proceedings,’” wrote Jadranka Stojanovska MD, MS, department of radiology at Michigan Medicine in Ann Arbor, and colleagues. “The noncitable or nonsource items count only toward the numerator, but not toward the denominator and are identifiable as ‘editorials,’ ‘commentaries,’ ‘news,’ ‘letters to the editor’ etc. Including citations of noncitable items is one of the shortcomings of the JIF. It favors journals that publish larger numbers of noncitable items that attract many citations.”
The team’s proposed metric, adjusted citation rate (CR), on the other hand, would only look at citations from those citable items. The authors put this metric to the test, determining the CR for 20 radiology journals. Overall, the CR and JIF were similar for 14 journals, higher for four journals and lower for two journals. Radiology, Investigative Radiology and European Radiology remained at the top of the list, even with this new metric.
“We developed an alternative and complementary metric for calculating JIF that reflects the quality of the journal,” the authors concluded.