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CR: Data Catalog Vocabulary (DCAT) - Version 2

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Date: Thu, 03 Oct 2019 13:11:00 +0000
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Data Catalog Vocabulary (DCAT) - Version 2


feedback due by: 2019-10-31


DCAT is an RDF vocabulary designed to facilitate interoperability between data catalogs published on the Web. This document defines the schema and provides examples for its use. 

DCAT enables a publisher to describe datasets and data services in a catalog using a standard model and vocabulary that facilitates the consumption and aggregation of metadata from multiple catalogs. This can increase the discoverability of datasets and data services. It also makes it possible to have a decentralized approach to publishing data catalogs and makes federated search for datasets across catalogs in multiple sites possible using the same query mechanism and structure. Aggregated DCAT metadata can serve as a manifest file as part of the digital preservation process. 

The namespace for DCAT terms is http://www.w3.org/ns/dcat# 

The suggested prefix for the DCAT namespace is dcat

Status of the Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/. 

This document defines a major revision of the original DCAT vocabulary ([VOCAB-DCAT-20140116]) in response to new use cases, requirements and community experience since that publication. This revision extends the original DCAT standard in line with community practice while supporting diverse approaches to data description and dataset exchange. The main changes to the DCAT vocabulary have been: 
  * loosening of constraints in class and property definitions to promote re-use of terms and modularity 
  * addition of a dcat:Resource class for representing any asset than can be included in the catalog, this is now the super-class of dcat:Dataset 
  * addition of dcat:DataService, as a sub-class of dcat:Resource, to support catalog service end-points providing access to data assets 
  * addition of ways to represent loosely structured catalogs, where there is no distinction between a dataset and its distributions 
  * more details for the ways of representing dataset provenance and quality 
  * an alignment between the DCAT vocabulary and the schema.org vocabulary  

This new version of the vocabulary updates and expands the original but preserves backward compatibility. A full list of the significant changes (with links to the relevent github issues) is described in § D. Change history. 

The exit criteria for CR will focus on v2 new features that replicate features that were included in application profiles of v1 as a way of remedying missing and necessary elements. The exit criteria also include recent commitments by organisations such as EC Joinup to adopt the DCAT v2 model in their work - see https://joinup.ec.europa.eu/solution/abr-specification-registry-registries/document/specification-registry-registries-version-meeting-september. Implementation will be evidenced by showing use of the new properties/classes (or terms with equivalent meaning) in implementations of catalogs. 

Issues, requirements, and features that have been considered and discussed by the Data eXchange Working Group but have not been addressed due to lack of maturity or consensus are collected in GitHub. Those believed to be a priority for a future release are in the milestone DCAT Future Priority Work. 

DCAT history 

The original DCAT vocabulary was developed and hosted at the Digital Enterprise Research Institute (DERI), then refined by the eGov Interest Group, and finally standardized in 2014 [VOCAB-DCAT-20140116] by the Government Linked Data (GLD) Working Group. 

This revised version of DCAT was developed by the Dataset Exchange Working Group in response to a new set of Use Cases and Requirements [DCAT-UCR] gathered from peoples&#x27; experience with the DCAT vocabulary from the time of the original version, and new applications that were not considered in the first version. A summary of the changes from [VOCAB-DCAT-20140116] is provided in § D. Change history. 

External terms 

DCAT incorporates terms from pre-existing vocabularies where stable terms with appropriate meanings could be found, such as foaf:homepage and dct:title. Informal summary definitions of the externally-defined terms are included in the DCAT vocabulary for convenience, while authoritative definitions are available in the normative references. Changes to definitions in the references, if any, supersede the summaries given in this specification. Note that conformance to DCAT (§ 4. Conformance) concerns usage of only the terms in the DCAT vocabulary specification, so possible changes to other external definitions will not affect the conformance of DCAT implementations. 

Please send comments The Working Group invites publishers to describe their catalogs and datasets with the revised version of DCAT described in this document and to report their implementations following the instruction to reporting DCAT revised implementations . The information gathered through this means will be augmented by further analysis of implementation available on the Web. The Working Group expects to adduce the combined set of evidence when requesting that the Director advance this document to Proposed Recommendation.

This document was published by the Dataset Exchange Working Group as a Candidate Recommendation. This document is intended to become a W3C Recommendation.

GitHub Issues are preferred for discussion of this specification. Alternatively, you can send comments to our mailing list. Please send them to public-dxwg-comments@w3.org (archives).

W3C publishes a Candidate Recommendation to indicate that the document is believed to be stable and to encourage implementation by the developer community. This Candidate Recommendation is expected to advance to Proposed Recommendation no earlier than 31 October 2019.

Please see the Working Group&#x27;s implementation report.

Publication as a Candidate Recommendation does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is governed by the 1 March 2019 W3C Process Document.
Received on Thursday, 3 October 2019 13:11:01 UTC

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