This report presents Deliverable D2.1, Challenges assessment, of the RIECS-Concept project: Towards a Pan-European Research Infrastructure for Excellent Citizen Science. The deliverable analyses the technical challenges associated with the development of a European research infrastructure for excellent citizen science. It examines the current landscape of citizen science platforms, tools, and services, with attention to interoperability, scalability, data standards, validation, governance-related technical constraints, and long-term sustainability. The report combines desk research, analysis of EU-funded citizen science initiatives, platform mapping, and domain-specific cases in environment and biodiversity, health, and climate. It identifies fragmentation as a central challenge across technological, data, standards, resource, and community dimensions. The report also proposes strategic directions for RIECS, including federated and modular infrastructure design, shared metadata schemas, open APIs, FAIR and CARE-aligned data practices, participatory co-design, and support for responsible use of emerging technologies such as artificial intelligence. The deliverable serves as an initial reference point for subsequent RIECS tasks, including technical requirements, service catalogue development, and organisational challenge analysis.
Godoy et al. (2025) studied this question.