Average and global impact of a set of journals

Abstract

In this note we clarify some notions concerning citations, publications, and their quotients: impact and indifference (a measure of invisibility, introduced in this article). In particular, we show that the slope of the regression line of the impact as a function of the number of publications is positive if and only if the global impact, i.e. the impact of the set of all journals under consideration, is larger than the average impact of all journals.