RDF Schema for IPTC Subject Reference System

RDF Schema representation of IPTC Subject Reference

This web page provides an RDF Schema representation of the IPTC Subject Reference System.

IPTC NewsML and Subject Reference System

The Subject Reference System (SRS) is an open standard, jointly developed by the International Press Telecommunications Council (IPTC) and the Newspaper Association of America. It is a controlled vocabulary designed to be used in any situation where news material needs to be categorized, including:

Within IPTC standards like the News Markup Language (NewsML), as attribute values drawn from a TopicSet; the News Industry Text Format (NITF) as elements and attributes; or within the Information Interchange Model (IIM), via new DataSets.
In other content classification systems, as a stand-alone vocabulary.

The IPTC Council was established to safeguard the telecommuincations interests of the World's Press. Its activities are mainly based on developing and publishing Industry Standards for the interchange of news data.

The Subject Reference System provides a hierarchy of subjects as metadata for categorising news. The main part of the SRS is hierarchy has three levels: Subject, Subject Matter and Subject Detail. SRS also includes other metadata elements like Subject Qualifier, Media Type, Media Type, and Gender.

The RDFS ontology we provide here includes only the Subject hierarchy part of SRS. If many users express a special interest in including other parts of SRS in the ontology, we might do so in the near future.

The Neptuno Project

The SRS ontology is a by-product of the Neptuno Project. The aim of this project is to apply Semantic Web technologies to improve the current state of the art in diverse aspects of the production, distribution and consumption of digital news. It is being conducted by two universities (Universidad Autónoma de Madrid and Universitat de Lleida), a news media company (Diari SEGRE), and a technology provider (iSOCO, S. A.). For more information see the project web page at http://nets.ii.uam.es/neptuno.

Translation to RDFS

The translation to RDFS has been achieved automatically from an XML representation provided on the IPTC web site, by means of a Java program based on the Jena RDF API. The decisions made for this translation include:

Three metaclasses are defined: Subject, SubjectMatter, and SubjectDetail.
An RDFS class is defined for each SRS category, as an instance of one of the three above metaclasses.
Subject codes are taken as the URIs of the RDF classes.
The SRS hierarchy is represented using the rdf:subclassOf property between the corresponding RDFS classes.
Each class takes four RDF properties after the SRS model:

title: with the name of the category.
explanation:a description of category.
changeComment.
changeVersion

All symbols belong to the namespace http://nets.ii.uam.es/iptc#.

An example of how the translation has been done is sown next.

The following fragment in XML language (taken from the IPTC SRS site):

	<Topic Duid="sr01000000">
		<TopicType Scheme="IptcTopicType" FormalName="Subject"/>
		<FormalName Scheme="IptcSubjectCodes">01000000</FormalName>
		<Description xml:lang="en-GB" Variant="Name">arts, culture and entertainment</Description>
		<Description xml:lang="en-GB" Variant="Explanation">Matters pertaining to the advancement and refinement of the human mind, of interests, skills, tastes and emotions</Description>
		<Description xml:lang="en-GB" Variant="ChangeComment">none</Description>
		<Description xml:lang="en-GB" Variant="ChangeVersion">0</Description>
	</Topic>
	<Topic Duid="sr01001000">
		<TopicType Scheme="IptcTopicType" FormalName="SubjectMatter"/>
		<FormalName Scheme="IptcSubjectCodes">01001000</FormalName>
		<Description xml:lang="en-GB" Variant="Name">archaeology</Description>
		<Description xml:lang="en-GB" Variant="Explanation">NA</Description>
		<Description xml:lang="en-GB" Variant="ChangeComment">none</Description>
		<Description xml:lang="en-GB" Variant="ChangeVersion">0</Description>
	</Topic>

is translated in RDF Schema to:

	<iptc:Subject rdf:about="&iptc;01000000"
		iptc:changeComment="none"
	 	iptc:changeVersion="0"
	 	iptc:title="arts, culture and entertainment"
	 	rdfs:label="arts, culture and entertainment">
		<iptc:explanation>Matters pertaining to the advancement and refinement of the human mind, of interests, skills, tastes and emotions</iptc:explanation>                              
	</iptc:Subject>
	<iptc:SubjectMatter rdf:about="&iptc;01001000"
	 	iptc:changeComment="none"
	 	iptc:changeVersion="0"
	 	iptc:explanation="NA"
	 	iptc:title="archaeology"
	 	rdfs:label="archaeology">
		<rdfs:subClassOf rdf:resource="&iptc;01000000"/>
	</iptc:SubjectMatter>

The metaclasses are defined as follows:

	<rdfs:Class rdf:about="&iptc;Subject"
	 	rdfs:label="Subject">
		<rdfs:subClassOf rdf:resource="&rdfs;Class"/>
	</rdfs:Class>
	<rdfs:Class rdf:about="&iptc;SubjectDetail"
	 	rdfs:label="SubjectDetail">
		<rdfs:subClassOf rdf:resource="&iptc;SubjectMatter"/>
	</rdfs:Class>
	<rdfs:Class rdf:about="&iptc;SubjectMatter"
	 	rdfs:label="SubjectMatter">
		<rdfs:subClassOf rdf:resource="&iptc;Subject"/>
	</rdfs:Class>

And the properties are:

<rdf:Property rdf:about="&iptc;changeComment"
	 rdfs:label="changeComment">
	<rdfs:domain rdf:resource="&iptc;Subject"/>
	<rdfs:range rdf:resource="&rdfs;Literal"/>
</rdf:Property>
<rdf:Property rdf:about="&iptc;changeVersion"
	 rdfs:label="changeVersion">
	<rdfs:domain rdf:resource="&iptc;Subject"/>
	<rdfs:range rdf:resource="&rdfs;Literal"/>
</rdf:Property>
<rdf:Property rdf:about="&iptc;explanation"
	 rdfs:label="explanation">
	<rdfs:domain rdf:resource="&iptc;Subject"/>
	<rdfs:range rdf:resource="&rdfs;Literal"/>
</rdf:Property>
<rdf:Property rdf:about="&iptc;title"
	 rdfs:label="title">
	<rdfs:domain rdf:resource="&iptc;Subject"/>
	<rdfs:range rdf:resource="&rdfs;Literal"/>
</rdf:Property>

Download

For convenience, we provide a Protege .pprj file where templates have been customized to better visualize the classes in the Protégé environment. In particular, the display slot has been set to the slot iptc:title instead of :NAME which would show the SRS code.

The SRS ontology: iptc-srs.rdfs (351 KB)
Protégé project file: iptc-srs.pprj

Contact

For any question or comment please contact javier.bravo@uam.es, pablo.castells@uam.es.