Abstract
"Impact Factor" (IF) of Journal Citation Reports published by Thomson Reuters (or ISI) is applied to performance evaluation of researchers at research institutions, despite the warning by the publisher that IF should be used only for journal evaluations. But it takes several years to get meaningful citation counts for individual papers. The IF seems to be the only indicator instantly available for the annual evaluations, and it would be quite effective as an early approximation. The author proposes IDV: Impact Deviation Value, a normalized index comparable across fields, based on deviation values of IFs in each field. The actual IDVs are calculated and analyzed to demonstrate the effects with comparison with usual IFs. Special account for the situation of Japanese journals will also be added.
