title: Sense and nonsense about the impact factor.
abstract: The impact factor is based on citations of papers published by a scientific journal. It has been published since 1961 by the Institute for Scientific Information. It may be regarded as an estimate of the citation rate of a journal's papers, and the higher its value, the higher the scientific esteem of the journal. Although the impact factor was originally meant for comparison of journals, it is also used for assessment of the quality of individual papers, scientists and departments. For the latter a scientific basis is lacking, as we will demonstrate in this contribution.
authors.affiliation: Department of Clinical and Experimental Cardiology, University of Amsterdam, Netherlands. t.opthof@amc.uva.nl
authors.forename: T
authors.initials: T
authors.lastname: Opthof
mesh_terms: D015706:Bibliometrics; D019451:Information Management; D010506:Periodicals as Topic; D011786:Quality Control; D012106:Research