DCAT-AP and its extensions: Context and evolution

One of the main challenges that arise when addressing an Open Data initiative is to define the information architecture and facilitate interoperability between data catalogs published by different portals on the Web. In order to solve this challenge, the World Wide Web Consortium (W3C) published the Data Catalog Vocabulary (DCAT), an RDF vocabulary to describe data catalogs based on 3 key concepts: catalog, dataset and distribution.

Based on this vocabulary, and within the JoinUP project, a collaborative platform created by the European Commission, an international group of experts developed the DCAT Application profile for data portals in Europe (DCAT-AP): a specification that describes restrictions (such as properties range) on the DCAT model. The objective is to facilitate homogenization and cross-searching, using metadata, between different European data portals generated by public sector and placed at citizens disposal for reuse.

The report DCAT-AP and its extensions: context and evolution, developed within the Aporta Initiative framework, arose to ​​ contextualize and delve into DCAT-AP, and DCAT vocabulary. The report includes a description of both publications, as well as a definition of the agencies and institutions involved in its definition. In addition, the report address differences between territores when they adapt this application profile.

Expansions and changes of the national extensions of DCAT-AP

Some countries of the European Union have adapted the DCAT-AP specification to respond to their own requirements and needs in appropriate way, modifying property cardinality and range restrictions. This is the case of Belgium, Germany, Ireland, Italy, the Netherlands, Norway, Sweden, Switzerland and Spain.

Although the report includes all the different national extensions, it is specially focused on the analysis of Spain situation, where the Norma Técnica de Interoperabilidad de Reutilización de recursos de información (NTI-RISP) establishes the common framework related to the opening and use of documents and information resources produced or guarded by the public administration. This Technical Standard seeks to ensure information persistence and formats use, as well as to promote the appropriate terms and use conditions. The NTI-RISP standard is prior to first DCAT and DCAT-AP versions, which has generated some variations.

Finally, the report ends with a description of the two DCAT-AP sector extensions: GeoDCAT-AP, focused on the exchange of descriptions of geospatial datasets and services, and StatDCAT-AP, related statistical data and services.