As a policy goal, open science can be traced back to the European Commission’s launch of the European Research Area (ERA) in 2000. However, the idea for a European Open Science Cloud (EOSC) was first mentioned in these terms in 2015, in the communication A Digital Single Market Strategy for Europe (COM (2015) 192 final), in the part of the text where the Commission proposed a set of initiatives focused on the building of a data economy. This idea was later welcomed by the European Council.
Since its inception, the purpose of the EOSC has been to create a space where not only publicly funded research outputs are openly available, but where EU researchers can publish, find, and reuse data, publications, software, tools and services for scientific and research purposes in a place modelled by commons standards all over the EU. The EOSC has been designed to connect all EU researchers and research outputs and is intended to act as an intermediary between these and all fragmented and non-interoperable data/research repositories or data locations (across different scientific domains, countries, governance models, access policies – you name it).
Currently, the EOSC has a tripartite governance. Its federated model conceptualized by the Commission requires strategic coordination between the Commission, the participating countries represented in the EOSC Steering Board (the Member States’ public authorities plus the corresponding ones from Associated Countries), and the research community represented by the EOSC Association, to finance, monitor and support the implementation of the EOSC in Europe.
Since the launch of the idea of the European Open Science Cloud, the Commission knew which was the main issue to solve: “how to maximize the incentives for sharing data (…)?”. In its Communication, the Commission proposed several ideas to address this challenge, which have been almost fully (if not completely) implemented, such as making all scientific data produced by EU funds open by default or developing awareness campaigns. Another solution would be through rewards: “Researchers who make research data open and FAIR for reuse (…) data should be rewarded, both in their career assessment and in the evaluation of projects (initial funding, review of performance and impact). This should go hand in hand with other career policies in universities and research institutions (appointments, promotions etc.).”
The fact is that, since 2016, the EU policy focus on areas directly connected to data has increased dramatically, and the EOSC is part of this. For example, the recent EU Data Strategy (2020) incorporates the EOSC in the EU data spaces map. The EOSC Multi-Annual Roadmap (MAR) 2025 and 2026–2027 (MAR) introduces as its first objective to “ensure that Open Science practices and skills are rewarded and taught, becoming the ‘new normal’”. It introduces a pivotal figure for the future of the EOSC: the data steward. According to MAR, a data steward at an institution in the EU would be responsible for controlling data usage, ensuring the application of the principles of Open Science, FAIRness of data and all research policies as determined by the EOSC governance (EC, Member States and EU research and academic stakeholders). MAR includes as one of its priorities at the European and national levels the implementation of data stewardship curricula, and at the institutional level the offer of “core Open Science and FAIR training to researchers at all levels and [recognition of] these skills as important for professional development”.
In a recent international forum on Open Science, several EU national policymakers voiced the concern that data stewardship was not close to research centers or attributed as a secondary function, namely, to positions such as Chief Data Officers or even given to the researchers themselves. Going even further than MAR, the participants in this forum concluded that data stewardship should be “recognized as a profession in its own right” and duly integrated into each research organization structure. Even if slightly, there is a difference between the MAR approach (data stewardship skills training and rewarding researchers’ work relevant to the EOSC transition) and the second approach (professionalization of the data stewards). The relevance of the second approach becomes even more evident if we consider that the recognition of the value of data stewardship is among MAR’s main points.
Both approaches, especially the second one, may face problems of coordination or harmonization of their implementation across the EU, namely because of differences in Member States’ academic facilities and resources. It is important to mention that one does not exclude the other. This begs the question, however, whether the implementation of FAIR data and Open Science can really be realized, especially in the long run, through the reskilling of researchers or as a secondary responsibility. Moreover, will the deployment of new secondary tasks to researchers’ responsibilities, adding to existing administrative overload, have negative effects on the development of research initiatives, merit or evaluation? Professionalization is the better way to protect both research and researchers.
The fact is that data stewardship is a fundamental aspect of the future of the EU and the success of its data-driven future. New responsibilities may require new powers. In a world facing numerous threats that affect Big Data and Artificial Intelligence, the European Open Science Cloud is a powerful tool to combat disinformation and academic fraud. Its power will be protected by its purposeful guards, the data stewards.
 This openness is compliant with the idea “as open as possible and as closed as necessary”: “Open access must be the default setting (…), allowing for proportionate limitations only in duly justified cases of personal data protection, confidentiality, IPR concerns, national security or similar (…)”, reports the 2017 EOSC Declaration (available at https://eosc-portal.eu/sites/default/files/eosc_declaration.pdf).
 FAIR data principle: “Findable, Accessible, Interoperable and Reusable”.
 Initially, the Commission presented three possible models for the EOSC: the fragmented model (as existed before the current EOSC); the totally centralized model (where researchers would access a single site with centralized norms and governance defined by the European Commission; the Commission considered the adoption of this model by the Member-States as highly unlikely); and the federated model (consisting of a common governance framework; universal entry point; GDPR compliant). The third model was the model adopted. For more information, see https://commission.europa.eu/system/files/2020-11/eosc_strategic_implementation_roadmap_large.pdf.
 Albania, Armenia, Bosnia and Herzegovina, Faroe Islands, Georgia, Iceland, Israel, Moldova, Montenegro, North Macedonia, Norway, Serbia, Türkiye, and Ukraine. See https://ec.europa.eu/transparency/expert-groups-register/screen/expert-groups/consult?lang=en&groupID=3756.
 Through the application of the EU funds attributed to the EOSC detailed in the Memorandum of Understanding for the Co-programmed European Partnership for the European Open Science Cloud (EOSC). See https://www.eosc.eu/sites/default/files/EOSC_Memorandum_30_July_2021.pdf.
 COM (2016) 178 final, Communication “European Cloud Initiative – Building a competitive data and knowledge economy in Europe”, available at
 To access a panoramic perspective on the EU Data Strategy and its Regulatory Acts, see https://www.prometheusnetwork.eu/publications/prometheus-publication-eu-data-strategy-a-multifaceted-perspective-from-southern-european-countries/