The June 2009 issue of PLoS One, a peer-reviewed, open access journal published by the Public Library of Science, carries the article, “A Principle Component Analysis of 39 Scientific Impact Measures“. This article provides, perhaps, the most thorough analysis of scientific journal citation analysis to date. The authors, Johan Bollen, Herbert Van de Sompel, Aric Hagberg, and Ryan Chute, analyzed thirty-nine types of impact measurements. The conclusions show that no perfectly reliable measure exists as yet. Users of the widely-utilized Journal Impact Factor (JIF) published in the Journal Citation Reports database are urged to use this measurement, in particular, with caution.