impact factor

INFORMATICS

Definition A term of art referring to the relative value of a particular article published in a peer-reviewed medical or scientific journal, which has been defined as the number of current citations to articles published in a specific journal in a 2-year period, divided by the total number of articles published in the same journal in those 2 years.

Comment The Institute for Scientific Information stresses that a journal’s impact factor is a meaningful indicator only when considered in the context of similar journals covering a single field of investigation or subject discipline.  

Reference www.isinet.com/isi/search/glossary/ (link broken, now links to Thomson Reuters)