Electronic Highways
Joys of journal rankings
In my capacity as liaison to the Graduate School of Education, I receive many requests from faculty who wish to ascertain the rankings of scholarly journals. This is particularly important for tenure-track faculty who are required to publish their research in prestigious journals. There are numerous ways of determining a journal’s ranking within an academic discipline, though their various definitions and formulas can be complicated. I will endeavor to explain in a simple way those measures that are most commonly used.
A journal’s impact factor refers to the average number of times an article published in the preceding two years is cited during a given year. Let’s use the Journal of Hypothetical Scenarios (JHS) and the publication year 2009 as an example. An impact factor of 1.5 means that articles published in JHS during 2007 and 2008 were cited, on average, 1.5 times during the year 2009. The five-year impact factor works the same way, but uses the previous five years of publication instead. It is important to note that the number of citations to an article come from the entire body of literature, as covered by a particular database. For this, the UB Libraries subscribe to the Journal Citation Reports database, which is powered by the Web of Science.
An Eigenfactor score is similar to the five-year impact factor in that it refers to the average number of times an article published in the preceding five years is cited during a given year. However, this measure weighs which journals have contributed to the score so that highly cited journals provide more influence than those that are less cited. The Eigenfactor score also removes references from one article in a journal to another article in the same journal, thus eliminating self-citations. The Journal Citation Reports database provides the most current information on this measure.
The H-index, also known as the Hirsch index or the Hirsch number, is a measure of the impact and productivity of an individual scholar. The measure is based on a set of the scholar’s most cited works and the number of citations to them in other publications. The index also can be applied to a group of scholars, an academic department, a country or a specific journal. However, h-index scores may vary significantly, based on where the bibliographic data is collected from. The most commonly used sources for this are Web of Science, Scopus and Google Scholar.
The SJR (SCImago Journal Rank) indicator is similar in nature to an Eigenfactor score; it weighs the influence of journals that generate citations and it limits the instances of self-citations. The SJR indicator’s distinguishing features are its three-year citation window and its source of bibliographic information: Scopus. Also of note, unlike Journal Citation Reports, SJR is a free Web source.
All the tools above use sophisticated equations to generate journal rankings and each one has its own idiosyncrasies, advantages and disadvantages. For assistance using and understanding them, contact your UB subject librarian.
—Christopher Hollister, Arts and Sciences Library
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