The Leiden ranking 2011/2012: Data collection, indicators, and interpretation

Abstract

The Leiden Ranking 2011/2012 is a ranking of universities based on bibliometric indicators of publication output, citation impact, and scientific collaboration. The ranking includes 500 major universities from 41 different countries. This paper provides an extensive discussion of the Leiden Ranking 2011/2012. The ranking is compared with other global university rankings, in particular the Academic Ranking of World Universities (commonly known as the Shanghai Ranking) and the Times Higher Education World University Rankings. The comparison focuses on the methodological choices underlying the different rankings. Also, a detailed description is offered of the data collection methodology of the Leiden Ranking 2011/2012 and of the indicators used in the ranking. Various innovations in the Leiden Ranking 2011/2012 are presented. These innovations include (1) an indicator based on counting a university's highly cited publications, (2) indicators based on fractional rather than full counting of collaborative publications, (3) the possibility of excluding non‐English language publications, and (4) the use of stability intervals. Finally, some comments are made on the interpretation of the ranking and a number of limitations of the ranking are pointed out.

The Herrero-Villar approach to citation impact

“…Comparing alternative evaluation procedures usually involves two key elements: (1) the extent of re-rankings, and (2) the importance of cardinal differences between those evaluations (see inter alia Waltman et al, 2012, andRuiz-Castillo &. As a first approximation, the first aspect might be partially revealed by rank correlation coefficients, and also by the Ulam distance between rankings.…”

“…14 The case of the University of Göttingen, which was ranked second in the 2011/2012 edition of the Leiden Ranking according to the MNCS indicator on the strength of a single highly cited publication, is cited as a good example of this problem (Waltman et al, 2012 Some comments are in order. Firstly, as we know, the ranking corresponding to the Top 25% and the HV 25% procedures is the same, but the dispersion of the index values is different.…”

Which are the "best" cities for psychology research worldwide?

“…The share of top-10% most highly cited publications in their subject category (publication year, document type) has become a de facto standard for the assessment of excellence at the institutional level (Bornmann, de Moya Anegón, & Leydesdorff, 2012;Bornmann, Mutz, Marx, Schier, & Daniel, 2011;Leydesdorff, Bornmann, Mutz, & Opthof, 2011;Tijssen & van Leeuwen, 2006;Tijssen, Visser, & van Leeuwen, 2002;Waltman et al, 2012). In this study we follow this classification and focus on the top-10% of papers published In a first step, all papers (n = 21,528) with the document type "article" published in 2007 and belonging to the subject categories "psychology," "psychology, applied," "psychology, biological," "psychology, clinical," "psychology, developmental," "psychology, educational," "psychology, experimental," "psychology, mathematical," "psychology, multidisciplinary," "psychology, psychoanalysis," and "psychology, social" were downloaded from the WoS (Social Science Citation Index).…”

Response: ‘Antibody crossreactivity between the tumour suppressor PHLPP1 and the proto‐oncogene β‐catenin’

“…We used the top 10% most-cited papers because these are equated with highly cited publications in many bibliometric publications [7][8][9][10]. Furthermore, this indicator is already used for the Leiden Ranking [11] and the SCImago Institutions Ranking [12].…”