The Leiden Ranking is produced by the Centre for Science and Technology Studies (CWTS) at Leiden University in the Netherlands. CWTS is a research center in the field of science and technology studies. The CWTS staff members contributing to the Leiden Ranking are listed here.
Our aim in producing the Leiden Ranking is twofold:
We produce the Leiden Ranking for policy makers, research managers, researchers, journalists, and anyone else with an interest in the scientific performance of universities. The Leiden Ranking does not consider the performance of universities in terms of teaching. We therefore expect the information provided by the Leiden Ranking to be of little value for students, and we advise students not to use the Leiden Ranking to choose where to study.
The Leiden Ranking is based on bibliographic data on scientific publications, in particular on articles published in scientific journals. As discussed in more detail here, we currently use Web of Science as our primary data source. CWTS has a special Web of Science license that enables us to use Web of Science data to produce the Leiden Ranking. Data from Web of Science is enriched by CWTS in various ways. In particular, as discussed here, we take a very careful approach to identify the publications of a university. For the open access indicators in the Leiden Ranking, we use data from OpenAlex. The Leiden Ranking does not use any data obtained directly from universities.
We aim to include as many universities as possible in the Leiden Ranking, but we do not have the resources to comprehensively cover all universities worldwide. A university therefore needs to have a certain minimum number of scientific publications in order to be included in the Leiden Ranking. This is discussed in more detail here.
The Leiden Ranking offers a responsible approach to university ranking.
We recognize that universities are complex organizations that have a variety of forms, contexts, and missions, which means that representing
the performance of a university in a single number does not make sense. Unlike other well-known university rankings, the Leiden Ranking
therefore presents a variety of indicators, enabling the performance of universities to be explored from a diversity of perspectives.
The exclusive focus on the scientific performance of universities also distinguishes the Leiden Ranking from other university rankings.
Other aspects of the performance of universities, in particular their contribution to teaching, are not considered in the Leiden Ranking.
Unlike other university rankings, the Leiden Ranking is based entirely on bibliographic data on scientific publications.
It relies on a sophisticated approach to data collection and provides a set of
advanced bibliometric indicators.
Most of the funding for the Leiden Ranking is currently provided by U-Multirank and the European Research Infrastructure for Science, technology and Innovation policy Studies (RISIS). The Leiden Ranking is also partly self-funded by CWTS.
Through CWTS B.V., a company affiliated with the CWTS research center and owned by Leiden University, we offer services for research evaluation and strategic decision making to universities and other research organizations. As part of this, we provide organizations with bibliometric indicators similar to those made available in the Leiden Ranking. Revenues generated through CWTS B.V. are used to sustain and strengthen the work of the CWTS research center.
We are currently exploring the possibility of creating an open edition of the Leiden Ranking that is fully transparent and reproducible. More information about this ongoing project can be found in this blog post.