Journal impact factor: a brief review.

At that time it did not occur to me that it would one day become the subject of widespread controversy. Like nuclear energy, the impact factor has become a mixed blessing. I expected that it would be used constructively while recognizing that in the wrong hands it might be abused. In the early 1960s Irving H. Sher and I created the journal impact factor to help select journals for the Science Citation Index (SCI). We knew that a core group of highly cited large journals needed to be covered in the SCI. However, we also recognized that small but important review journals would not be selected if we depended solely on simple publication or citation counts. 2