How Can Journal Impact Factors be Normalized across Fields of Science? An Assessment in terms of Percentile Ranks and Fractional Counts

Loet Leydesdorff, Ping Zhou, Lutz Bornmann

Using the CD-ROM version of the Science Citation Index 2010 (N = 3,705 journals), we study the (combined) effects of (i) fractional counting on the impact factor (IF) and (ii) tran…