The Z-index: A geometric representation of productivity and impact which accounts for information in the entire rank-citation profile

Alexander M. Petersen and Sauro Succi

Journal of Informetrics, 2013, vol. 7, issue 4, 823-832

Abstract: We present a simple generalization of Hirsch's h-index, Z≡h2+C/5, where C is the total number of citations. Z is aimed at correcting the potentially excessive penalty made by h on a scientist's highly cited papers, because for the majority of scientists analyzed, we find the excess citation fraction (C−h2)/C to be distributed closely around the value 0.75, meaning that 75% of the author's impact is neglected. Additionally, Z is less sensitive to local changes in a scientist's citation profile, namely perturbations which increase h while only marginally affecting C. Using real career data for 476 physicists careers and 488 biologist careers, we analyze both the distribution of Z and the rank stability of Z with respect to the Hirsch index h and the Egghe index g. We analyze careers distributed across a wide range of total impact, including top-cited physicists and biologists for benchmark comparison. In practice, the Z-index requires the same information needed to calculate h and could be effortlessly incorporated within career profile databases, such as Google Scholar and ResearcherID. Because Z incorporates information from the entire publication profile while being more robust than h and g to local perturbations, we argue that Z is better suited for ranking comparisons in academic decision-making scenarios comprising a large number of scientists.

Keywords: Science of science; Citation impact; Rank stability; h-Index (search for similar items in EconPapers)
Date: 2013
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Citations: View citations in EconPapers (4)

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Persistent link: https://EconPapers.repec.org/RePEc:eee:infome:v:7:y:2013:i:4:p:823-832

DOI: 10.1016/j.joi.2013.07.003

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