The inconsistency of the h‐index

Abstract

The h-index is a popular bibliometric indicator for assessing individual scientists. We criticize the h-index from a theoretical point of view. We argue that for the purpose of measuring the overall scientific impact of a scientist (or some other unit of analysis), the h-index behaves in a counterintuitive way. In certain cases, the mechanism used by the h-index to aggregate publication and citation statistics into a single number leads to inconsistencies in the way in which scientists are ranked. Our conclusion is that the h-index cannot be considered an appropriate indicator of a scientist's overall scientific impact. Based on recent theoretical insights, we discuss what kind of indicators can be used as an alternative to the h-index.We pay special attention to the highly cited publications indicator.This indicator has a lot in common with the h-index, but unlike the h-index it does not produce inconsistent rankings.

Completing h

“…(3.1) was also discussed in Refs. [3,4] in order to illustrate some of the fine-tuned arbitrariness inherent in the traditional definition of h. Similar work along these lines also appears in Refs. [5][6][7][8][9][10][11].…”

“…A few representative papers are listed in Refs. [3,4,7,8,. Proposals for modifying the h-index include…”

“…• increasing the weighting of very highly-cited papers, either through the introduction of intrinsic weighting factors or the development of entirely new indices which mix the h-index with other more traditional indices (such as total citation count) [3,4,7,8,[26][27][28][29][30][31][32];…”

“…This general point has also been emphasized in, e.g., Refs. [3][4][5][6]. More specifically, these two quantities (paper counts and citation counts) transform differently under community rescalings.…”

“…Indeed, this is only one of a number of such practical inconsistencies inherent in the traditional h-index; other similar inconsistencies are discussed in Refs. [3,4].…”