Last October I participated in a conference on research assessment in Capri, Italy. The various discussions and presentations at this meeting reminded me that there are still widespread misunderstandings-indeed, myths-about citation analysis, especially with respect to journal impact. For those readers who are not aficionados of citation analysis, journal impact factors as used in the Institute for Scientific Information's (ISI's) Journal Citation Reports are a simple ratio of citations and papers. They are calculated by dividing the number of current-year citations (for example, 1997) to a journal's papers published in the previous two years (that is, 1996 and 1995) by the combined total of these papers.
Journal impact factors are used for a variety of purposes. For example, librarians may consider impact factors, as well as several other important criteria, in their decisions on which journals to include in their collections. Journal impact has also become a staple in ...
