How to derive an advantage from the arbitrariness of the g-index

TL;DR

This paper examines the arbitrary nature of the g-index's threshold, proposes a standardized prefactor of 2 to make it comparable to the h-index, and discusses its implications for ranking scientists.

Contribution

It introduces a specific prefactor for the g-index to reduce arbitrariness and improve comparability with the h-index, based on a case study of physicists.

Findings

Prefactor of 2 aligns g-index values with h-index magnitude

G-index's ranking stability is less affected by the prefactor than h-index

Different prefactors may suit different research evaluation contexts

Abstract

The definition of the g-index is as arbitrary as that of the h-index, because the threshold number g^2 of citations to the g most cited papers can be modified by a prefactor at one's discretion, thus taking into account more or less of the highly cited publications within a dataset. In a case study I investigate the citation records of 26 physicists and show that the prefactor influences the ranking in terms of the generalized g-index less than for the generalized h-index. I propose specifically a prefactor of 2 for the g-index, because then the resulting values are of the same order of magnitude as for the common h-index. In this way one can avoid the disadvantage of the original g-index, namely that the values are usually substantially larger than for the h-index and thus the precision problem is substantially larger; while the advantages of the g-index over the h-index are kept. Like for the generalized h-index, also for the generalized g-index different prefactors might be more useful for investigations which concentrate only on top scientists with high citation frequencies or on junior researchers with small numbers of citations.