The objective of DCAT is quite simple, and was well received by the community open data since its publication as a recommendation of W3C in january 2014. This is: to provide an RDF vocabulary (a set of classes and properties) to describe clearly the content of datasets and catalogues of data on the web. Briefly, let us imagine an organisation that wants to issue a set of CSV files on certain economic indicators. Thanks to DCAT, this entity might provide actionable descriptions (RDF) by identifying those files as a catalogue ( dcat Catalogue: ), in which each particular file is a dataset ( dcat Dataset: ) which is identified from elements ( skos: Concept ) a controlled vocabulary, a thesaurus, a taxonomy, etc.
The DCAT-AP can be summarized as follows:
1. It does not introduce a new vocabulary . On the contrary, its aim is to define in a concrete manner the use of certain property and to the publication DCAT data within the european Union. In those areas necessary for the description of disks and datasets and they are not present in DCAT are used to recycle existing vocabularies of others (such as foaf: Document to identify those websites which published).
2. Defines a policy for the use of DCAT-AP by specifying what, classes and properties are mandatory or optional, as recommended in the implementation of the vocabulary within the european Union.
3. Policy establishes principles according to the publication and use of official DCAT-AP (Section 6 of the specification).
4. Discusses the use of controlled vocabularies (in SKOS) for the description of the topic of datasets, expanding the brief example; it is really important recommendation explicitly on the reuse of europeans, as vocabularies Eurovoc, which opens the door to possible DCAT-AP applications in the field of public procurement.
In addition are currently underway new developments on DCAT-AP in the following points:
1. Extension of DCAT-AP for the exchange of narratives for datasets and space services: GeoDCAT-AP . The working group has already published a first specification (v1.0), still under “ working draft ”. Its main objective is to provide a RDF syntax to combine the metadata schemes of the initiative WILL INSPIRE and ISO 19115:2003, according to the principles of conformity set by DCAT-AP.
2. Extension of DCAT-AP for joint publication of statistical data: StatDCAT-AP . With this objective has been recently established a working group, that among its first actions was to find relevant metadata common among different portals of publication of statistical data, such as Eurostat. Looking For similarities, StatDCAT-AP intended to be for RDF vocabulary Data Cube, while the SDMX metadata/EMS it is for the specification SDMX.
Finally, the european commission has opened a line of activity for the preparation of handbooks on implementation of DCAT-AP. In this regard, the open participation of various european organisations, contribute by providing actual experiences in implementing DCAT-AP and problems and challenges encountered in its implementation. However, this new specification and its early adoption by the European Data Portal is a very good sign for the world Open Data. The specification (v1.1) is published in the framework of the JoinUp project