Multiplicative versus fractional counting methods for co-authored publications : the case of the 500 universities in the Leiden ranking

This paper studies the assignment of responsibility to the participants in the case of co-authored scientific publications. In the conceptual part, we establish that the key shortcoming of the full counting method is its incompatibility with the use of additively decomposable citation impact indicators. In the empirical part of the paper, we study the consequences of adopting the address-line fractional or multiplicative counting method. For this purpose, we use a Web of Science dataset consisting of 3.6 million articles published in the 2005-2008 period, and classified into 5,119 clusters. Our research units are the 500 universities in the 2013 edition of the CWTS Leiden Ranking. Citation impact is measured using the Mean Normalized Citation Score, and the Top 10% indicators. The main findings are the following. Firstly, although a change of counting methods alters co-authorship and citation impact patterns, cardinal differences between co-authorship rates and between citation impact values are generally small. Nevertheless, such small differences generate considerable re-rankings between universities. Secondly, the universities that are more penalized by the adoption of a fractional rather than a multiplicative approach are those with a small co-authorship rate for the citation distribution as a whole, a large co-authorship rate in the upper tail of this distribution, a low citation impact performance, and a small number of solo publications.Ruiz-Castillo acknowledges financial support from the Spanish MEC through grant ECO2014-55953-P

Field-normalized citation impact indicators and the choice of an appropriate counting method

Bibliometric studies often rely on field-normalized citation impact indicators in order to make comparisons between scientific fields. We discuss the connection between field normalization and the choice of a counting method for handling publications with multiple co-authors. Our focus is on the choice between full counting and fractional counting. Based on an extensive theoretical and empirical analysis, we argue that properly field-normalized results cannot be obtained when full counting is used. Fractional counting does provide results that are properly field normalized. We therefore recommend the use of fractional counting in bibliometric studies that require field normalization, especially in studies at the level of countries and research organizations. We also compare different variants of fractional counting. In general, it seems best to use either the author-level or the address-level variant of fractional counting

A review of the literature on citation impact indicators

Citation impact indicators nowadays play an important role in research evaluation, and consequently these indicators have received a lot of attention in the bibliometric and scientometric literature. This paper provides an in-depth review of the literature on citation impact indicators. First, an overview is given of the literature on bibliographic databases that can be used to calculate citation impact indicators (Web of Science, Scopus, and Google Scholar). Next, selected topics in the literature on citation impact indicators are reviewed in detail. The first topic is the selection of publications and citations to be included in the calculation of citation impact indicators. The second topic is the normalization of citation impact indicators, in particular normalization for field differences. Counting methods for dealing with co-authored publications are the third topic, and citation impact indicators for journals are the last topic. The paper concludes by offering some recommendations for future research

Differences in citation impact across countries

Using a large dataset, indexed by Thomson Reuters, consisting of 4.4 million articles published in 1998-2003 with a five-year citation window for each year, this paper studies country citation distributions in a partition of the world into 36 countries and two geographical areas in the all-sciences case and eight broad scientific fields. The key findings are the following two. Firstly, the shape of country citation distributions is highly skewed and very similar to each other across all fields. Secondly, differences in country citation distributions appear to have a strong scale factor component. The implication is that, in spite of the skewness of citation distributions, international comparisons of citation impact in terms of country mean citations capture well such scale factors. The empirical scenario described in the paper helps understanding why, in each field and the all-sciences case, the country rankings according to (i) mean citations and (ii) the percentage of articles in each country belonging to the set formed by the 10% of the more highly cited papers are so similar to each other.Albarrán acknowledges additional financial support from the Spanish MEC through grants ECO2009-11165 and ECO2011-29751, and Ruiz-Castillo through grant SEJ2007-67436

Ranking authors using fractional counting of citations : an axiomatic approach

This paper analyzes from an axiomatic point of view a recent proposal for counting citations: the value of a citation given by a paper is inversely proportional to the total number of papers it cites. This way of fractionally counting citations was suggested as a possible way to normalize citation counts between fields of research having different citation cultures. It belongs to the “citing-side” approach to normalization. We focus on the properties characterizing this way of counting citations when it comes to ranking authors. Our analysis is conducted within a formal framework that is more complex but also more realistic than the one usually adopted in most axiomatic analyses of this kind

Differences in citation impact across countries

Using a large data set, indexed by Thomson Reuters, consisting of 4.4 million articles published in 1998–2003 with a 5-year citation window for each year, this article studies country citation distributions for a partitioning of the world into 36 countries and two geographical areas in eight broad scientific fields and the all-sciences case. The two key findings are the following. First, country citation distributions are highly skewed and very similar to each other in all fields. Second, to a large extent, differences in country citation distributions can be accounted for by scale factors. The Empirical situation described in the article helps to understand why international comparisons of citation impact according to (a) mean citations and (b) the percentage of articles in each country belonging to the top 10% of the most cited articles are so similar to each other.The authors acknowledge financial support by Santander Universities Global Division of Banco Santander. Albarrán acknowledges additional financial support from the Spanish MEC through grants ECO2009–11165 and ECO2011–29751, and Ruiz-Castillo through grant ECO2010–19596

Individual and Field Citation Distributions in 29 Broad Scientific Fields

Using a large unique dataset consisting of 35.1 million authors and 105.3 million articles published in the period 2000-2016, which are classified into 29 broad scientific fields, we search for regularities at the individual level for very productive authors with citation distributions of a certain size, and for the existence of a macro-micro relationship between the characteristics of a scientific field citation distribution and the characteristics of the individual citation distributions of the authors belonging to the field. Our main results are the following three. Firstly, although the skewness of individual citation distributions varies greatly within each field, their average skewness is of a similar order of magnitude in all fields. Secondly, as in the previous literature, field citation distributions are highly skewed and the degree of skewness is very similar across fields. Thirdly, the skewness of field citation distributions is essentially explained in terms of the average skewness of individual authors, as well as individuals’ differences in mean citation rates and the number of publications per author. These results have important conceptual and practical consequences: to understand the skewness of field citation distributions at any aggregate level we must simply explain the skewness of the individual citation distributions of their very productive authors.This is the second version of a paper with the same title published in this series in January 2018. J. Ruiz-Castillo acknowledges financial support from the Spanish MEC through grants ECO2014-55953-P and MDM 2014-0431, as well as grant MadEco-CM (S2015/HUM-3444) from the Comunidad Autónoma de Madrid. Research assistantship by Patricia Llopis, as well as conversations with Ricardo Mora, and especially Vincent Traag, are gratefully acknowledged. All remaining shortcomings are the authors’ sole responsibility

Congress UPV Proceedings of the 21ST International Conference on Science and Technology Indicators

This is the book of proceedings of the 21st Science and Technology Indicators Conference that took place in València (Spain) from 14th to 16th of September 2016. The conference theme for this year, ‘Peripheries, frontiers and beyond’ aimed to study the development and use of Science, Technology and Innovation indicators in spaces that have not been the focus of current indicator development, for example, in the Global South, or the Social Sciences and Humanities. The exploration to the margins and beyond proposed by the theme has brought to the STI Conference an interesting array of new contributors from a variety of fields and geographies. This year’s conference had a record 382 registered participants from 40 different countries, including 23 European, 9 American, 4 Asia-Pacific, 4 Africa and Near East. About 26% of participants came from outside of Europe. There were also many participants (17%) from organisations outside academia including governments (8%), businesses (5%), foundations (2%) and international organisations (2%). This is particularly important in a field that is practice-oriented. The chapters of the proceedings attest to the breadth of issues discussed. Infrastructure, benchmarking and use of innovation indicators, societal impact and mission oriented-research, mobility and careers, social sciences and the humanities, participation and culture, gender, and altmetrics, among others. We hope that the diversity of this Conference has fostered productive dialogues and synergistic ideas and made a contribution, small as it may be, to the development and use of indicators that, being more inclusive, will foster a more inclusive and fair world

DISSERTATION

This particular research aims to investigate the p-index or performance indicator proposed by Prathap in 2010. The concept of analogy between such branches of physics as mechanical and electrical physics, kinetics, thermodynamics and scientometric field was assumed, and it seems to be an incredibly interesting consilience. Perceiving standard bibliometric measures as an energy which each paper carries, allow us to operate with these numbers in a new way. P index, which is calculated as p=X1/3 =(iC)1/3=(c/pC)1/3=(c2/p)1/3, where C is the total number of citations received and P is the total number of publications, were computed for 499 top productive authors affiliated with Malaysian institutuions, who were retrieved from Web of Science Database..