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

TL;DR

The paper discusses the methodology, indicators, and innovations of the Leiden Ranking 2011/2012, a university ranking based on bibliometric data, and compares it with other global rankings.

Contribution

It introduces new indicators and methodological improvements in the Leiden Ranking 2011/2012, enhancing the assessment of university research performance.

Findings

Introduction of highly cited publications indicator

Use of fractional counting for collaborations

Inclusion of stability intervals for rankings

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. 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.