Submitted:
24 April 2025
Posted:
24 April 2025
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Abstract
Keywords:
Introduction
COs Concept: Origin and Roots
COs over Time: A Multifaceted Conceptual Trajectory
COs as Research Infrastructures: Essential Functions
Technical Functions
Social Functions
COs as Infrastructures: Essential Characteristics
COs Types: Tailored and Open COs
Conclusion
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
Abbreviations
| COs | Citizen Observatories |
| CSPs | Citizen Science Platforms |
| CBM | Community-Based Monitoring |
| VGI | Volunteered Geographic Information |
| ICT | Information and Communication Technologies |
| EC | European Commission |
| EEA | European Environment Agency |
| NGOs | Non-Governmental Organisations |
| EMBIMOS | Environmental and Sustainability Participatory Information Systems |
| ICM-CSIC | Institut de Ciències del Mar Consejo Superior de Investigaciones Científicas |
| UOC | Universitat Oberta de Catalunya (Open University of Catalonia) |
References
- Rathnayake C, Joshi S, Cerratto-Pargman T. Mapping the current landscape of citizen-driven environmental monitoring: a systematic literature review. Sustainability: Science, Practice and Policy. 2020 Dec 10;16(1):326–34. [CrossRef]
- Fraisl D, Campbell J, See L, Wehn U, Wardlaw J, Gold M, et al. Mapping citizen science contributions to the UN sustainable development goals. Sustain Sci. 2020 Nov 1;15(6):1735–51. [CrossRef]
- Fraisl D, See L, Campbell J, Danielsen F, Andrianandrasana HT. The Contributions of Citizen Science to the United Nations Sustainable Development Goals and Other International Agreements and Frameworks. Citizen Science: Theory and Practice. 2023 Jun 27;8(1):27. [CrossRef]
- Woods SM, Daskolia M, Joly A, Bonnet P, Soacha K, Liñan S, et al. How Networks of Citizen Observatories Can Increase the Quality and Quantity of Citizen-Science-Generated Data Used to Monitor SDG Indicators. Sustainability. 2022 Jan;14(7):4078. [CrossRef]
- Ajates R, Hager G, Georgiadis P, Coulson S, Woods M, Hemment D. Local action with global impact: The case of the grow observatory and the sustainable development goals. Sustainability. 2020;12(24):1–17. [CrossRef]
- Fritz S, See L, Carlson T, Haklay M (Muki), Oliver JL, Fraisl D, et al. Citizen science and the United Nations Sustainable Development Goals. Nat Sustain. 2019 Oct;2(10):922–30.
- Cooper C, Hunter DL, Archer JM, Caballero-Gomez H, Hawn C, Johnson V, et al. A Positionality Tool to Support Ethical Research and Inclusion in the Participatory Sciences. Citizen Science: Theory and Practice [Internet]. 2024 Nov 19 [cited 2025 Jan 28];9(1). Available from: https://theoryandpractice.citizenscienceassociation.org/articles/10.5334/cstp.684. [CrossRef]
- Hunter D, Greg N, Balgopal M. What’s in a name? The paradox of citizen science and community science. Frontiers in Ecology and the Environment. 2023 May 3;21. [CrossRef]
- Rathnayake C, Joshi S, Cerratto-Pargman T. Mapping the current landscape of citizen-driven environmental monitoring: a systematic literature review. Sustainability: Science, Practice and Policy. 2020 Dec 10;16(1):326–34. [CrossRef]
- Haklay M (Muki), Dörler D, Heigl F, Manzoni M, Hecker S, Vohland K. What Is Citizen Science? The Challenges of Definition. In: Vohland K, Land-Zandstra A, Ceccaroni L, Lemmens R, Perelló J, Ponti M, et al., editors. The Science of Citizen Science [Internet]. Cham: Springer International Publishing; 2021 [cited 2022 Mar 3]. p. 13–33. Available from: . [CrossRef]
- Liu HY, Dörler D, Heigl F, Grossberndt S. Citizen Science Platforms. In: Vohland K, Land-Zandstra A, Ceccaroni L, Lemmens R, Perelló J, Ponti M, et al., editors. The Science of Citizen Science [Internet]. Cham: Springer International Publishing; 2021 [cited 2021 Sep 14]. p. 439–59. Available from: . [CrossRef]
- CitSci.org [Internet]. [cited 2025 Feb 14]. Available from: https://citsci.org/.
- Anecdata.org [Internet]. [cited 2025 Mar 28]. Available from: https://www.anecdata.org/welcome.
- eBird T. 2023 Year in Review: eBird, Merlin, Macaulay Library, and Birds of the World - eBird [Internet]. [cited 2025 Mar 28]. Available from: https://ebird.org/ebird/news/2023-year-in-review.
- Observation.org [Internet]. Observation.org. [cited 2025 Feb 14]. Available from: https://observation.org/stats/.
- Site Stats · iNaturalist [Internet]. iNaturalist. [cited 2025 Feb 14]. Available from: https://www.inaturalist.org/stats.
- Observations [Internet]. iNaturalist. [cited 2025 Feb 14]. Available from: https://www.inaturalist.org/observations.
- Välkommen till Artportalen - Artportalen [Internet]. [cited 2025 Apr 8]. Available from: https://www.artportalen.se/.
- Liljeblad J. Data about ArtPortalen. 2025.
- Stats - Pl@ntNet identify [Internet]. [cited 2025 Mar 28]. Available from: https://identify.plantnet.org/stats.
- Our Story | Project Noah [Internet]. [cited 2025 Feb 14]. Available from: https://projectnoah.org/our-story.
- Observations [Internet]. MINKA. [cited 2025 Feb 14]. Available from: https://minka-sdg.org/observations.
- Liu HY, Grossberndt S, Kobernus M. Citizen Science and Citizens’ Observatories: Trends, Roles, Challenges and Development Needs for Science and Environmental Governance. In: Ubiquity Press [Internet]. Ubiquity Press; 2017 [cited 2020 Apr 30]. [CrossRef]
- Wehn U, Almomani A. Incentives and barriers for participation in community-based environmental monitoring and information systems: A critical analysis and integration of the literature. Environmental Science & Policy. 2019 Nov;101:341–57. [CrossRef]
- WeObserve consortium. Roadmap for the uptake of the Citizen Observatories’ knowledge base. Report submitted to the European Commission. [Internet]. WeObserve; 2021 [cited 2022 Aug 31]. Available from: https://iiasa.dev.local/.
- Brenton P, von Gavel S, Vogel E, Lecoq ME. Technology infrastructure for citizen science. In: Hecker S, Haklay M, Bowser A, Makuch Z, Vogel J, Bonn A, editors. Citizen Science [Internet]. UCL Press; 2018 [cited 2021 Mar 9]. p. 63–80. (Innovation in Open Science, Society and Policy). Available from: https://www.jstor.org/stable/j.ctv550cf2.12.
- Momino JM, Piera J, Jurado E. Citizen observatories as advanced learning environments. In: ANALYZING THE ROLE OF CITIZEN SCIENCE IN MODERN RESEARCH. 701 E CHOCOLATE AVE, STE 200, HERSEY, PA 17033-1240 USA: IGI GLOBAL; 2017. p. 192–212. (Advances in knowledge acquisition transfer and management (AKATM) book series).
- Gold, Margaret. D2.1 EU Citizen Observatories Landscape Report - Frameworks for mapping existing CO initiatives and their relevant communities and interactions [Internet]. European Citizen Science Association ECSA - WeObserve; 2018 [cited 2019 Nov 4]. Available from: https://zenodo.org/record/3670895#.XpdqKplS_b0.
- Montargil F, Santos V. Communication with citizens in the first EU citizen observatories experiences. In: Dias Rouco J.C. VBJ, editor. Academic Conferences Limited; 2017. p. 96–103. (Proceedings of the European Conference on e-Government, ECEG; vol. Part F129463). Available from: https://repositorio.ipl.pt/bitstream/10400.21/7830/1/Montargil%20and%20Santos_ECDG%202017_Proceedings.pdf.
- Piera J, Justamante Á. Citizen science through Cos4Cloud. EU Research. 2022;33(Winter 2022):27–9.
- Etaligent.NET. EU BON - Citizens’ Observatories: Empowering European Society - Open Conference [Internet]. EUBON. [cited 2025 Apr 1]. Available from: http://www.eubon.eu//news/11597_Citizens%E2%80%99%20Observatories:%20Empowering%20European%20Society%20-%20Open%20Conference.
- Grainger A. Citizen Observatories and the New Earth Observation Science. Remote Sensing. 2017 Feb;9(2):153. [CrossRef]
- Angulo Marcial N. ¿Qué son los observatorios y cuáles son sus funciones? Innovación Educativa. 2009;9(47):5–17.
- Silva R. ¿Qué es un Observatorio Ciudadano? Apuntes para la discusión. Vinculos Sociología, análisis y opinión. 2013;4:189–202.
- Natal A, Díaz O. Observatorios ciudadanos: nuevas formas de participación en la sociedad. 2014.
- Keseru I, Wuytens N, Macharis C. Citizen observatory for mobility: a conceptual framework. Transport Reviews. 2019 Jul 4;39(4):485–510.
- Zooniverse [Internet]. [cited 2020 Jun 7]. Available from: https://www.zooniverse.org/talk/15/8777?comment=89320&page=2.
- O’Grady M, Mangina E. Adoption of Responsible Research and Innovation in Citizen Observatories. Sustainability. 2022 Jan;14(12):7379. [CrossRef]
- Prem E, Sanz FS, Lindorfer M, Lampert D, Irran J. Open Digital Science. Final Study Report. eutema GmbH, ZSI and Universidad de Zaragoza.; 2016.
- mukih. Citizens Observatories: Empowering European Society [Internet]. Po Ve Sham - Muki Haklay’s personal blog. 2014 [cited 2025 Apr 1]. Available from: https://povesham.wordpress.com/2014/12/04/citizens-observatories-empowering-european-society/.
- Liu HY, Kobernus M, Broday D, Bartonova A. A conceptual approach to a citizens’ observatory – supporting community-based environmental governance. Environ Health. 2014 Dec 12;13(1):107. [CrossRef]
- Hager G, Gold M, Wehn U, Ajates R, See L, Woods M, et al. Onto new horizons: insights from the WeObserve project to strengthen the awareness, acceptability and sustainability of Citizen Observatories in Europe. JCOM. 2021 Oct 11;20(6):A01. [CrossRef]
- European Commission. FP7 Cooperation Work Programme 2012: Environment (including climate change) [Internet]. 2012 [cited 2022 Feb 17]. Available from: https://ec.europa.eu/research/participants/data/ref/fp7/89467/f-wp-201201_en.pdf.
- Ciravegna F, Huwald H, Lanfranchi V, Wehn de Montalvo U. Citizen observatories: The WeSenseIt Vision. Inspire Conference; 2013 Jun 23; Florence,.
- Mazumdar S, Lanfranchi V, Ireson N, Wrigley S, Bagnasco C, Wehn U, et al. Citizens observatories for effective Earth observations: the WeSenseIt approach. Environmental Scientist. 2016 Aug 4;25(2):56–61.
- Hunt N, O’Grady M, Muldoon C, Kroon B, Rowlands T, Wan J, et al. Citizen Science: A Learning Paradigm for the Smart City? Interaction Design and Architectures. 2015 WIN;(27):44–65.
- Wehn U, Evers J. The social innovation potential of ICT-enabled citizen observatories to increase eParticipation in local flood risk management. Technology in Society. 2015 Aug;42:187–98. [CrossRef]
- Palacin-Silva M, Seffah A, Heikkinen K, Porras J, Pyhälahti T, Sucksdorff Y, et al. State-of-the Art Study in Citizen Observatories: Technological Trends, Development Challenges and Research Avenues [Internet]. Finnish Environment Institute; 2016 [cited 2019 Nov 4]. Available from: https://helda.helsinki.fi/handle/10138/164810.
- European Commission. Coordination of citizens’ observatories initiatives. TOPIC ID: SC5-19-2017. [Internet]. 2016 [cited 2022 Feb 17]. Available from: https://ec.europa.eu/info/funding-tenders/opportunities/portal/screen/opportunities/topic-details/sc5-19-2017.
- Ferri M, Wehn U, See L, Fritz S. The Value of Citizen Science for Flood Risk Reduction: Cost-benefit Analysis of a Citizen Observatory in the Brenta-Bacchiglione Catchment. Hydrology and Earth System Sciences Discussions. 2019 Dec 17;1–27. [CrossRef]
- Hemment D, Woods M, Ajates R, Cobley A, Xaver A. Enhancing collective intelligence through citizen science: The case of the GROW citizens’ observatory. In: Collective Intelligence 2019 Proceedings [Internet]. Association for Computing Machinery (ACM); 2019 [cited 2020 Apr 18]. p. 1–4. Available from: https://discovery.dundee.ac.uk/en/publications/enhancing-collective-intelligence-through-citizen-science-the-cas-2.
- Ajates R, Hager G, Georgiadis P, Coulson S, Woods M, Hemment D. Local action with global impact: The case of the grow observatory and the sustainable development goals. Sustainability. 2020;12(24):1–17. [CrossRef]
- Wehn U, Pfeiffer E. Guidelines for Citizen Observatories and Future Recommendations [Internet]. Groundtruth 2.0; 2020 [cited 2021 Mar 4]. Available from: https://gt20.eu/wp-content/uploads/2020/06/GT2.0-D1.13-Guidelines-for-Citizen-Observatories-FINAL.pdf.
- Gold M, Wehn U. Mission Sustainable: Fostering an enabling environment for sustainable Citizen Observatories. WeObserve policy brief 2. 2020 [cited 2021 Sep 8]; Available from: https://zenodo.org/record/4001672.
- Heaton L. Chains of Participation in Producing Biodiversity Infrastructures: Digital Reconfigurations of Scientific Work. SCIENCE AS CULTURE. 2022 Jan 21. [CrossRef]
- Spasiano A. Citizen science and socio-technical perspective: Reflection on a possible integration. In: Bednar P., Bednar P., Nolte A., Nolte A., Rajanen M., Islind A.S., et al., editors. CEUR Workshop Proc [Internet]. CEUR-WS; 2021. p. 117–24. Available from: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120943384&partnerID=40&md5=30f668db460ded9455052648735a4e17.
- UNESCO. Bolstering open science infrastructures for all - UNESCO Digital Library [Internet]. 2022 [cited 2023 Apr 26]. Available from: https://unesdoc.unesco.org/ark:/48223/pf0000383711.
- European Commission. European Research Infrastructures - European Commission [Internet]. 2020 [cited 2024 Dec 21]. Available from: https://research-and-innovation.ec.europa.eu/strategy/strategy-research-and-innovation/our-digital-future/european-research-infrastructures_en.
- Albagli S, Py H, Iwama AY. Data geovisualization and open and citizen science - the LindaGeo platform prototype. DIGITAL HUMANITIES QUARTERLY. 2020;14(2).
- Skarlatidou A, Hamilton A, Vitos M, Haklay M. What do volunteers want from citizen science technologies? A systematic literature review and best practice guidelines. JCOM [Internet]. 2019 Jan 17 [cited 2020 Mar 22];18(01). Available from: https://jcom.sissa.it/archive/18/01/JCOM_1801_2019_A02. [CrossRef]
- Corsín Jiménez A. The Right to Infrastructure: A Prototype for Open Source Urbanism. Environ Plan D. 2014 Apr 1;32(2):342–62.
- Fecher B, Kahn R, Sokolovska N, Völker T, Nebe P. Making a Research Infrastructure: Conditions and Strategies to Transform a Service into an Infrastructure. Science and Public Policy. 2021 Aug 1;48(4):499–507. [CrossRef]
- Star S, Ruhleder K. Steps Toward an Ecology of Infrastructure: Design and Access for Large Information Spaces. Information Systems Research. 1996 Mar 1;7:111–34. [CrossRef]
- Güntsch A, Overmann J, Ebert B, Bonn A, Le Bras Y, Engel T, et al. National biodiversity data infrastructures: ten essential functions for science, policy, and practice. BioScience. 2025 Feb 1;75(2):139–51. [CrossRef]




| Citizen observatory | Ref. | Host Institution and country | Number of projects hosted | Number of users-accounts* | Number of observations |
|---|---|---|---|---|---|
| Environmental and Biodiversity | |||||
| CitSci.Org | [12] | Colorado State University. USA. | >1.400 | >17.000 | >165.000 observations >2.1 million measurements |
| Anecdata | [13] | MDI Biological Laboratory, Maine, USA. | >340 | >19,400 | >160,600 |
| Biodiversity | |||||
| eBird | [14] | Cornell Lab, Cornell University, USA. | - | >930,000 | >1,6 billion |
| Observation.org | [15] | Observation International. The Netherlands. |
- | >470.000 | >269 million |
| iNaturalist | [16,17] | iNaturalist org. USA. | >180.000 | >3.5 million | >226 million |
| ArtPortalen | [18,19] | SLU, Swedish Environmental Protection Agency, Swedish University of Agricultural Science. Sweden. | >5,000 | >90,000 | >110 million |
| Pl@ntNet | [20] | CIRAD, INRAE, INRIA and IRD. France. | - | >7,6 million* | >25 million |
| Project Noah | [21] | New York University. USA. | >1.000 | >450.000 | >920.000 |
| MINKA | [22] | EMBIMOS research group. Institut of Ciències del Mar (ICM-CSIC). Spain. | >300 | >1.400 | >380.000 |
| Authors | Ref. | Definition focused on COs’ main role | Year |
|---|---|---|---|
| European Commission | [43] |
|
2012 |
| Ciravegna et al. * in Mazumdar et al. | [44,45] |
|
2013 |
| Liu et al. | [41] |
|
2014 |
| Hunt et al. | [46] |
|
2015 |
| Wehn et al. | [47] |
|
2015 |
| Palacin-Silva et al. | [48] |
|
2016 |
| European Commission | [49] |
|
2017 |
| Grainger | [32] |
|
2017 |
| Momino et al. | [27] |
|
2017 |
| Montargil and Santos | [29] |
|
2017 |
| Ferri et al. | [50] |
|
2019 |
| Hemment et al. | [51] |
|
2019 |
| Ajates et al. | [52] |
|
2020 |
| Groundtruth 2.0 | [53] |
|
2020 |
| Gold et al. | [54] |
|
2020 |
| Rathnayake et al. | [1] |
|
2020 |
| Hager et al. | [42] |
|
2021 |
| WeObserve Consortium | [25] |
|
2021 |
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