Radicchi, F; Fortunato, S; Castellano, C Universality of citation distributions: Toward an objective measure of scientific impact PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 105 (45): 17268-17272 NOV 11 2008

[Eugene Garfield]

E-mail Address: claudio.castellano at romal.infn.it 

Author(s): Radicchi, F (Radicchi, Filippo); Fortunato, S (Fortunato, 
Santo); Castellano, C (Castellano, Claudio) 

Title: Universality of citation distributions: Toward an objective measure 
of scientific impact 

Source: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED 
STATES OF AMERICA, 105 (45): 17268-17272 NOV 11 2008 

Language: English 

Document Type: Article 

Author Keywords: bibliometrics; analysis; h index 

Keywords Plus: SCIENTOMETRIC INDICATORS; FIELD-NORMALIZATION; CROSS-FIELD; 
H-INDEX; SCIENCE; PUBLICATION; PERFORMANCE; OUTPUT; POWER; MODEL 

Abstract: We study the distributions of citations received by a single 
publication within several disciplines, spanning broad areas of science. 
We show that the probability that an article is cited c times has large 
variations between different disciplines, but all distributions are 
rescaled on a universal curve when the relative indicator c(f) = c/c(0) is 
considered, where c(0) is the average number of citations per article for 
the discipline. In addition we show that the same universal behavior 
occurs when citation distributions of articles published in the same 
field, but in different years, are compared. These findings provide a 
strong validation of cf as an unbiased indicator for citation performance 
across disciplines and years. Based on this indicator, we introduce a 
generalization of the h index suitable for comparing scientists working in 
different fields. 

Addresses: [Castellano, Claudio] Univ Roma La Sapienza, CNR, Natl Inst 
Phys Matter, Ctr Stat Mech & Complex, I-00185 Rome, Italy; [Castellano, 
Claudio] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy; 
[Radicchi, Filippo; Fortunato, Santo] Inst Sci Interchanged Fdn, Complex 
Networks Lagrange Lab, I-10133 Turin, Italy 

Reprint Address: Castellano, C, Univ Roma La Sapienza, CNR, Natl Inst Phys 
Matter, Ctr Stat Mech & Complex, Piazzale A Moro 2, I-00185 Rome, Italy. 

E-mail Address: claudio.castellano at romal.infn.it 

Cited Reference Count: 29 

Times Cited: 0 

Publisher: NATL ACAD SCIENCES 

Publisher Address: 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA 

ISSN: 0027-8424 

DOI: 10.1073/pnas.0806977105 

29-char Source Abbrev.: PROC NAT ACAD SCI USA 

ISO Source Abbrev.: Proc. Natl. Acad. Sci. U. S. A. 

Source Item Page Count: 5 

Subject Category: Multidisciplinary Sciences 

ISI Document Delivery No.: 373OP 

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