Impact Factor Statement

The EASE Statement on Inappropriate Use of Impact Factors was published in November 2007 after a consultation exercise.  It records how, although the journal impact factor was developed as a means to measure the impact of scientific journals, its use has been extended to measuring the quality of scientific journals, the quality of individual articles and the productivity of individual researchers. 

EASE recommends that journal impact factors are used only - and cautiously - for measuring and comparing the influence of entire journals, but not for the assessment of single papers, and certainly not for the assessment of researchers or research programmes either directly or as a surrogate.