Centre for Science and Technology Studies Centre for Science and Technology Studies 2333AL Leiden Zuid Holland 31715273909


CWTS is an interdisciplinary institute at Leiden University. Its research staff come from a broad and diverse spectrum of specialized academic fields ranging from psychology, political science, literature studies and information science to computer science, economics, physics and chemistry.

Institute Board

Clara Calero-Medina

Clara Calero-Medina is a senior researcher and director of innovation and impact at the Centre for Science and Technology Studies (CWTS) at Leiden University. She is a coordinator of the Information & Openness focal area and a member of the Engagement & Inclusion focal area.

Tjitske Holtrop

Tjitske Holtrop is a senior researcher and director of culture and inclusion at the Centre for Science and Technology Studies (CWTS) at Leiden University. She is a coordinator of the Engagement & Inclusions focal area and a member of the Evaluation & Culture focal area.

Wolfgang Kaltenbrunner

Wolfgang Kaltenbrunner is a senior researcher and director of research and education at the Centre for Science and Technology Studies (CWTS) at Leiden University. He is a coordinator of the Evaluation & Culture focal area.

Ludo Waltman

Ludo Waltman is professor of Quantitative Science Studies and scientific director at the Centre for Science and Technology Studies (CWTS) at Leiden University. He is a coordinator of the Information & Openness focal area and a member of the Evaluation & Culture focal area. Ludo is co-chair of the Research on Research Institute (RoRI).

Board Support

Ilse Schuitema

Board secretary and institute manager. Focuses on human resource management, policy making, and strategic advisory of the board. Background in academic research and
education. PhD in Neuropsychology.

Academic Staff

Anestis Amanatidis

Junior researcher. Anestis employs Techno-Anthropological methods and perspectives to investigate the complex relations between science and society.

Zeynep Anli

Researcher and project coordinator, working mainly on Leiden Ranking and various European Union projects on research assessment, open science, organizational research, bibliometric data, gender analysis and data curation.

Jackie Ashkin

PhD candidate and researcher with FluidKnowledge. Her research examines the relationship between evaluation practices and knowledge production in marine science through an ethnographic lens.

Juan Pablo Bascur Cifuentes

PhD candidate and member of the QSS research group. His research focuses on machine learning and natural language processing of papers to improve literature searches.

Rinze Benedictus

Part-time PhD candidate who also works as staff advisor at the UMC Utrecht and is involved in the Science in Transition initiative. He analyzes institutional policy-making processes that shape research evaluation practices.

Louise Bezuidenhout

Louise Bezuidenhout is a social science researcher who specializes on issues relating to Open Science, data sharing and access. Her research is broadly oriented around themes such as justice and access, inclusion and marginalization and equity.

Sarah Rose Bieszczad

PhD candidate in the Science and Evaluation Studies (SES) group as part of the Sarah de Rijcke’s Fluid Knowledge Project. 

Carole de Bordes

Researcher and bibliometric consultant. Carole joined CWTS in 2018 and is currently involved in several performance and evaluation studies for independent contract research at CWTS B.V.

Andre Brasil

Researcher and member of the UNESCO Chair for Diversity and Inclusion in Global Science. André is a research fellow at the Research on Research Institute (RoRI) and he is also affiliated with the Brazilian Agency for Support and Evaluation of Graduate Education (CAPES).

Francesco Colona

Marie Curie Research Fellow. His research focuses on how the production of visual data on public and private oceanographic vessels and their impact on ocean sciences research practices.

Rodrigo Costas

Senior researcher. Rodrigo's research focuses on the development of new social media metrics (altmetrics), new scientometric applications at the individual-level and the study of funding acknowledgements.

Jonathan Dudek

Junior researcher. Jonathan is working in the research line of 'altmetrics', studying online science communication and new data sources for altmetrics.

Nees Jan van Eck

Senior researcher, head of data science, and coordinator of the Information & Openness focal area. Nees Jan's research focuses on infrastructures and the development of tools and algorithms to support research assessment, science policy, and scholarly communication.

Soohong Eum

Soohong Eum is a PhD candidate. His research interests are governance of public R&D system, and the relationship between organizational structure and innovation. 

Thomas Franssen

Senior researcher. Thomas works on the intersection of valuation studies, sociology and STS. Previous research analyzed the constitutive effects of the rise of competitive project funding on the epistemic and organizational properties of research. His current interests are the history of scientometrics and valuation cultures in the humanities and its effects on knowledge production.

Huilin Ge

PhD candidate at the Centre for Science and Technology Studies(CWTS) of Leiden University.  Her PhD research focuses on brain drain dynamics at the global-level-relationships with collaboration dynamics.

Dan Gibson

Researcher focusing on the identification and analysis of academic and research organisations for the Leiden Ranking database.

Margaret Gold

Researcher and Coordinator of the Citizen Science Lab. Her research focuses on the policy and environmental governance impacts of Citizen Observatories, and she specializes in the application of collaborative approaches to co-create new Citizen Science initiatives.

Kathleen Gregory

Researcher. Kathleen conducts research exploring scholarly communication practices and infrastructures, including those related to open science, research data, and peer review.

Laurens Hessels

Professor by special appointment at CWTS. Laurens conducts research into the processes and mechanisms of knowledge valorization and into methods and indicators for evaluating valorization.

Kwun Hang (Adrian) Lai

PhD candidate of the Quantitative Science Studies research group at the Centre for Science and Technology Studies (CWTS)

Thed van Leeuwen

Senior researcher at CWTS. Thed's research focuses on the relationships between (reforms of) research evaluation, open scholarship, and research integrity, as well as on the research assessment of scholarly activity in the social sciences, the humanities, and law. He is co-editor of the OUP journal Research Evaluation.

Ingeborg Meijer

Senior researcher in research policy and evaluation with a focus on biomedicine and healthcare R&I. Ingeborg’s main goal is to make sure that society is able to use research.

Biegzat Mulati

PhD candidate. Biegzat’s PhD research project aims to depict both the theoretical and empirical aspects that configurate the influences and relationships between science making and policy making at the global level.

Ed Noyons

Everard (Ed) Christiaan Marie Noyons is a senior researcher at the Centre for Science and Technology Studies (CWTS) at Leiden University. He is a member of the Engagement & Inclusion and Evaluation & Culture focal areas. He is also a board member of CWTS BV.

Ana Parron Cabanero

PhD candidate at the Centre for Science and Technology Studies (CWTS), Leiden University. 

Ton van Raan

Emeritus professor of Quantitative Studies of Science. Ton's research focuses on the application of bibliometric indicators in research evaluation, science as a self-organizing complex system, statistics of bibliometric indicators, ranking and benchmarking of universities, and mapping of science.

Ismael Rafols

Ismael Rafols is a senior researcher at CWTS. He works on the development of novel approaches to S&T indicators for informing evaluation, foresight and research strategies. His current focus is on research priority setting, in particular for societal challenges such as Sustainable Development Goals (SDGs) in health and agriculture.

Renate Reitsma

PhD Candidate at the CWTS’ FluidKnowledge project. She looks at deep-sea mining research to understand how public-private partnerships address the transition to a clean energy economy. Driven by a passion for sustainable ocean science and governance, she holds a Master’s degree in Sustainable Development from Utrecht University.

Andrea Reyes Elizondo

Researcher. Andrea’s research focusses on the different academic and health science systems and the relationships between them. She is also involved in projects concerning research integrity in scientific publishing and research support organisations.

Sarah de Rijcke

Sarah de Rijcke is professor of Science, Technology and Innovation Studies at the Centre for Science and Technology Studies (CWTS) at Leiden University and dean of the Faculty of Social and Behavioural Sciences. Her work examines the interactions between science governance and knowledge creation. Sarah is a member of the Engagement & Inclusion and Evaluation & Culture focal areas. Between 2019 and 2023, she served as scientific director of CWTS.

Alex Rushforth

Assistant professor. Alex works in the social studies of science, specializing in research evaluation, uses of indicators and research assessment reforms. 

Marta Sienkiewicz

PhD candidate and member of the Science and Evaluation Studies (SES) research group. She studies new tools used in research evaluation, particularly those which aim to capture wider notions of research quality, excellence and impact.

Jorrit Smit

Postdoctoral researcher in the Responsible Innovation project ‘Catalyzing Knowledge Ecosystems’. Jorrit focuses on the intersection of the politics, spatiality and societal value of scientific research. 

Anouk Spelt

Researcher and project manager at Citizen Science Lab. Responsible for coordinating several Citizen Science projects and community manager of Citizen Science Nederland.

Clifford Tatum

Researcher. Focusing on Open Science in the context of Responsible Research Assessment. Member of the focal areas Information & Openness and Evaluation & Culture.

Robert Tijssen

Emeritus professor of Science and Innovation Studies at Leiden University. Professor at Stellenbosch University (South Africa). Robert’s current interests focus on contributions of universities and higher education institutions to local or regional socio-economic development.

Vincent Traag

Senior researcher and bibliometric consultant. Vincent's research focuses on complex networks and social dynamics. He holds a Master in sociology and a PhD in applied mathematics, and tries to combine the two in his work.

Judit Varga

Researcher with the FluidKnowledge project. Her research examines how combining methods from science and technology studies (STS) with scientometrics can help study the relationship between (e)valuation and knowledge production in Ocean Science.

Martijn Visser

Researcher and PhD candidate. Martijn's research focuses on data sources for the measurement of research performance.

Dongyi Wang

PhD candidate. His research focuses on how to alleviate inequality among science communication occupations.

Inge van der Weijden

Senior researcher, lecturer and PhD coordinator. Inge conducts both qualitative and quantitative research on the motivation, selection and evaluation of scholars in order to better understand career development of scientists within and outside academia.

Tim Willemse

Researcher with a background in Innovation Studies. Tim holds a MSc in Innovation Sciences and a BSc in Science and Innovation Management. 

Paul Wouters

Paul Wouters is emeritus professor of scientometrics.. Paul is interested in how evaluation systems have developed and are creating new constraints for the development of knowledge. He is also interested in the history of science in general and the role of information systems in these histories in particular.

Qianqian Xie

PhD candidate at the Centre for Science and Technology Studies (CWTS) of Leiden University in the Netherlands. Her PhD research focuses on how research addresses social problems, especially in health.

Alfredo Yegros

Senior researcher and member of the Engagement & Inclusion focal area. Alfredo's research interests include, among others, public-private interactions and knowledge flows, science-technology linkages, and relationship between science/technology and innovation.

Jochem Zuijderwijk

PhD candidate. Jochem is working on a PhD thesis that focuses on the formative effects of new incentive and reward systems in biomedicine within the Science and Evaluation Studies (SES) group.



Visiting Academic Staff

Tung Tung Chan

Visiting Researcher. Tung Tung’s research focuses on Research Intelligence, Responsible Research and Innovation (RRI) and Open Science.

Giovanni Colavizza

Visiting researcher focusing on full-text analytics and the humanities. Giovanni is interested in computational approaches to model the use scholars make of language, in science within Wikipedia, and in understanding the social and intellectual organisation of humanities disciplines.

Eleonora Dagiene

External PhD candidate. Eleonora is working on a PhD thesis that focuses on the quantitative research evaluation and its unintended consequences within the Quantitative Science Studies (QSS) research group.

Jamal El Ouahi

External PhD candidate. Jamal’s research interests include quantitative science studies as well as research evaluation with a focus on the Middle-East and Africa region.

Zhichao Fang

Visiting researcher. Zhichao’s research interests focus on the development and application of altmetrics and usage metrics.

Márcia Ferreira Gonçalves

Visiting researcher: Márcia is interested in evolutionary innovations, networks and complex systems, combining statistical physics and economics in order to understand the conditions underlying creativity and innovation processes in science.

Javad Hayatdavoudi

External PhD candidate. Javad is working on a PhD thesis that focuses on research assessment and funding policies from a scientometric-constructivist perspective.

Gaston Heimeriks

Visiting professor at CWTS. His research addresses evolutionary knowledge dynamics to understand how geographic regions, economic sectors and scientific fields create new ideas. 

Dmitrii Kochetkov

External PhD candidate. Dmitrii's major focus is policy analysis, research interests include (but not limited to) research evaluation, university rankings, excellence initiatives in higher education, preprinting, and open peer review.

Vincent Lariviere

Professor at Université de Montréal and visiting professor at CWTS. At Université de Montréal, Vincent holds the Canada Research Chair on the Transformations of Scholarly Communication and is associate vice-president for planning and communications.

Marc Luwel

Visiting researcher. Marc's research focuses on performance-based funding in higher education and measuring outcome and impact of publicly funded research.

Noortje Marres

Professor at the Centre for Interdisciplinary Methodologies at Warwick University and Visiting Professor at CWTS. Noortje's work is concerned with participation in technological societies and contributes to the development of digital research methodologies, in particular issue mapping.

Philippe Mongeon

Postdoctoral researcher and member of the Science and Evaluation Studies research group. Philippe’s research interests include the relationship between evaluation practices and knowledge production, team science, and researchers’ data sharing and reuse behavior.

Tina Nane

Visiting researcher. Tina's research focuses on the statistical analysis and modeling of bibliometric data and citation networks.

Ton Nederhof

Visiting researcher. Ton's research focuses on research evaluation and bibliometric analysis in general (including in the social sciences and humanities).

Ivo de Nooijer

External PhD candidate. Ivo is working on a PhD thesis that investigates licensing negotiations between universities and companies, supervised by Prof. Robert Tijssen and Prof. Sarah de Rijcke.

Susana Oliveira Henriques

External PhD candidate. Susana is working on a PhD thesis that focuses on innovation in scholarly communication and peer review, with a special focus on dissemination and quality control of biomedical research. 

Philip Purnell

External PhD Candidate working on regional differences in research and publication behaviour.

Narmin Rzayeva

External PhD candidate. Narmin is working on a PhD thesis that focuses on systematic research of peer review process in scientific journals and covers methods of harmonization of existing peer review models and development of alternatives.

Alexander Schniedermann

External PhD candidate. Alexander Schniedermann works on standardization in biomedical research.

Sarah Schönbauer

Guest researcher and Erwin Schrödinger Fellow (FWF Austria). Her research focuses on the marine sciences, specifically on how marine scientists engage with environmental changes. 

Kirsten Vegt

External PhD candidate. Kirsten is working on a PhD thesis that focuses on the societal impact of citizen science, in particular on trust between stakeholders and their trust in the scientific processes and outcomes related to citizen science projects.

Niki Vermeulen

Visiting researcher, focusing on science and innovation policy and the organisation of research, with an emphasis on scientific collaboration.

Jian Wang

Assistant Professor at the Science Based Business Program, Faculty of Science, Leiden University.  

Verena Weimer

External PhD candidate. Verena is working on a PhD thesis that focuses on the quantification of openness in higher education teaching.

Jos Winnink

Visiting researcher at the Centre for Science and Technology Studies (CWTS).

Zohreh Zahedi

Visiting researcher and member of Quantitative Science Studies research group. Zohreh’s research focuses on studying the interactions between social media and science (Social Media Study of Science)

Technical Staff

Bram van den Boomen

Database developer and administrator. Bram is involved in the development and maintenance of the CWTS database system.

Hans den Os

Full stack developer. Hans has 15 years of experience developing web, desktop, and mobile applications on the .NET platform using a wide variety of Microsoft technologies. His current work focuses on web development using React and the ASP.NET Core framework.

Marketing & Sales Staff

Mark Neijssel

Sales director CWTS B.V. Mark is responsible for the development of the contract research activities for research performance studies, network analyses, and science mapping studies, as well as tailor-made training courses for clients.

Administrative Staff

Karin den Dulk


Liesbeth Schaap


Petra van der Weel

Coordinator CWTS Office. Petra is also the secretary of the Ethics Review Committee Social Sciences of FSW.


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