The
impact factor (
IF) of an
academic journal is a measure reflecting the average number of
citations to recent articles published in that journal. It is frequently used as a
proxy for the relative importance of a journal within its field, with journals with higher impact factors deemed to be more important than those with lower ones. The impact factor was devised by
Eugene Garfield, the founder of the
Institute for Scientific Information. Impact factors are calculated yearly starting from 1975 for those journals that are indexed in the
Journal Citation Reports.