Comparative analysis of DCAT-AP landscape for improving interoperability and accessibility of european open data.

Abstract

DCAT-AP is the common metadata standard adopted by many EU Member States, institutions, and organizations for publishing and reusing Open Data. In response to national and organizational requirements, several DCAT-AP National Profiles (NPs) have been developed to extend, specialise, or partially override the core specifications and introduce additional controlled vocabularies. While these profiles support local publishing needs, they also increase the complexity of harvesting, validation, and front-end rendering workflows in European Data Portal (EDP) and raise questions about interoperability and consistent metadata integration. To address these challenges, this paper presents a comparative analysis of the European DCAT-AP landscape, focusing on NPs that contribute a substantial volume of metadata to EDP. We introduce the DCAT-AP Profiles Analysis Methodology (DPAM) and the DCAT-AP Profiles Analysis Sheet (DPAS), a structured representation for DCAT-AP and its profiles. Using DPAM and DPAS, we systematically document, at multiple levels of detail, how seven NPs deviate from the core DCAT-AP specification in terms of added, omitted, changed, and deprecated elements. The results quantify the extent and nature of these deviations and explicate the trade-off between the modeling flexibility of RDF/DCAT-AP and the implementation complexity in real-world harvesting and presentation systems. The analysis provides: (i) an empirical basis for adapting harvesting and front-end components to profilespecific requirements, (ii) a baseline for Member States and standards bodies to review profile designs in line with DCAT-AP extension guidelines and identify potential violations as well as (iii) a reusable framework for monitoring and analyzing future DCAT-AP profiles.