WORKING DRAFT

Re3gistry RDF format


Status of this document

This report describes the current status of work on the RDF representation of records served by the Re3gistry and the INSPIRE Registry.

This specification is still work in progress, and it must be considered as unstable until the publication of its final version.

Changelog


Summary

The data schema of the content of the Re3gistry consists of 4 main entities, depicted in the following diagram:

Re3gistry conceptual schema

The registry is the service, whereas entitites register and item denote how the content served by the registry is organised. As shown in the diagram, items may include other items (referred to as child items). This is, e.g., the case of code lists, which are modelled as items, and code values, which are child items of code lists.

Entity item class is meant to denote the type of content corresponding to an item. Version 4 of the INSPIRE Registry includes the following ones: i.e., application schemas, (metadata) code lists, documents, feature concepts, glossary items, themes.

The proposed approach is as follows:
NOTE About item classes, it is to be considered whether to use other vocabularies in addition to SKOS. The mapping tables in the following sections include some proposals (marked with "?"- question mark).
The adopted vocabularies determine also the properties used to model the relationships linking the different entities:
  • dcat:dataset: links the registry to registers
  • dct:hasPart: links a register to an item, and an item to a child item
  • skos:inScheme: links any item modelled as a skos:ConceptScheme to its child items, which are modelled as skos:Concept's
In case of items organised hierarchically (e.g., some of the code lists), the proposed approach is as follows:
  • 1st-level items are modelled as skos:ConceptScheme's and all the rest are modelled as skos:Concept's
  • skos:topConceptOf is used to link the 2nd-level items to the corresponding parent
  • skos:hasTopConcept: inverse property of skos:topConceptOf
  • skos:broader is used to link items under the 2nd level to their parent

Proposed mappings

Used namespaces

Prefix Namespace URI Schema & documentation
adms http://www.w3.org/ns/adms# Asset Description Metadata Schema
dcat http://www.w3.org/ns/dcat# Data Catalog Vocabulary
dct http://purl.org/dc/terms/ DCMI Metadata Terms
foaf http://xmlns.com/foaf/0.1/ FOAF Vocabulary
prv http://purl.org/net/provenance/ns# The Provenance Vocabulary Core Ontology
rdf http://www.w3.org/1999/02/22-rdf-syntax-ns# Resource Description Framework (RDF): Concepts and Abstract Syntax
rdfs http://www.w3.org/2000/01/rdf-schema# RDF Vocabulary Description Language 1.0: RDF Schema
skos http://www.w3.org/2004/02/skos/core# SKOS Simple Knowledge Organization System - Reference
vann http://purl.org/vocab/vann/ VANN: A vocabulary for annotating vocabulary descriptions
xsd http://www.w3.org/2001/XMLSchema# XML Schema Part 2: Datatypes Second Edition

Entities

Components RDF classes Comments
Registry dcat:Catalog
Register dcat:Dataset
Item prv:DataItem
dcat:Dataset Only when the item has child items
Item classes RDF classes Other RDF classes
Theme skos:Concept
Application schema skos:Concept owl:Ontology?
Code list / Metadata code list skos:ConceptScheme
Code list value skos:Concept
Feature concept skos:Concept rdfs:Class?
Glossary item skos:Concept others?
Document foaf:Document dct:Standard?

Standard / common attributes

Attributes Registry, Register Item All items modelled as skos:Concept's Status
Base URI + URI name @rdf:about stable
URI name dct:identifier stable
Label dct:title +skos:prefLabel stable
Definition dct:description +skos:definition stable
Description vann:usageNote testing
Language dct:language stable
Status adms:status stable
This version owl:sameAs unstable
Latest version adms:last stable
Manager dct:publisher - unstable
Control body dct:creator - unstable
Owner dct:rightsHolder - stable

Content of RDF representation

  • What is in the original records concerning the registry, registers and items
  • Information on the available distributions - implicit in the original records – in terms of formats (and languages)
The part concerning distributions makes use of:
  • For formats:
    • URIs from the W3C File Format register [UUFFF] (this URI register is limited to serialisations of Semantic Web languages)
    • URIs from the IANA MIME media types registry [IANA-MT]
  • For languages:
    • URIs available in the corresponding authority table operated by the Metadata Registry of the Publications Office of the EU (OP) [MDR-LANG]
NOTE Alternatively to the IANA MIME media types registry, another option is to use the OP's authority table of file types [MDR-FT].

The OP's authority tables are already used in the metadata records of the EU Open Data Portal, and their use is recommended in the DCAT Application Profile for Data Portal in Europe (DCAT-AP).

Example of RDF representation

Registry

The example can be downloaded in the following RDF serialisations:

Register (code list register)

The example can be downloaded in the following RDF serialisations:

Item (code list)

The example can be downloaded in the following RDF serialisations:

Child item (code list value)

The example can be downloaded in the following RDF serialisations:

Attachments

re3gistry-data-schema.png - Re3gistry conceptual schema (13.4 KB) Andrea Perego, 01 Aug 2014 01:50 am

item-code-list.rdf - RDF representation of a code list (7.58 KB) Andrea Perego, 01 Aug 2014 03:01 am

child-item-code-list-value.rdf - RDF representation of a code list value (4.99 KB) Andrea Perego, 01 Aug 2014 03:02 am

registry.rdf - RDF representation of the record describing the registry (4.46 KB) Andrea Perego, 01 Aug 2014 03:33 am

register-code-list.rdf - RDF representation of the code list register (28.2 KB) Andrea Perego, 01 Aug 2014 03:33 am