What are Scientific Leaders? The Introduction of a Normalized Impact Factor

Abstract

We define a normalized impact factor (NIF) suitable for assessing in a simple way both the strength of scientific communities and the research influence of individuals. We define those with NIF a parts per thousand yenaEuro parts per thousand 1 as scientific leaders because they influence their peers at least as much as they are influenced by them. The NIF has two outstanding characteristics: (a) it has a clear and universal meaning and (b) it is robust against self-citation misuse. We show how a single lognormal function obtained from a simplified version of the NIF leads to a clear radiography of the corresponding scientific community. An illustrative application analyzes a community derived from the list of outstanding referees recognized by the American Physical Society in 2008.