MARC Relator Properties in Dublin Core Metadata

Element Refinement: Summary

According to the DCMI Abstract Model, a DC metadata description is a set of one or more statements about a single resource, and a statement is a two-part construct consisting of a reference to a property and a reference to a second resource, a value [DCMIAM]. The reference to the subject of the description is made by a URI (the "resource URI"). The reference to a property also takes the form of a URI (the "property URI"). The reference to the value may take the form of a URI or a "value representation". For the purposes of this discussion, the examples show the simplest cases where that reference takes the form of a URI (a "value URI") or a representation in the form of a string (a "value string").

Each statement asserts that a relationship of the type indicated by the property exists between two resources: the resource that is the subject of the description, and the value.

If the definitions of two properties are such that whenever two resources are related by the first property they are also related by the second property, the first property is said to "refine", or to be a "refinement" of the second property.

So for example, the definition of the property marcrel:CTG (Cartographer) is "A person or organization responsible for the creation of maps and other cartographic materials", and the definition of the property dc:contributor is "An entity responsible for making contributions to the content of the resource". A cartographer is always "An entity responsible for making contributions to the content of the resource", so the marcrel:CTG property refines the dc:contributor property (see note [1]).

Conversely, with the information that the marcrel:CTG property refines the dc:contributor property, if an application encounters the description:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://www.loc.gov/loc.terms/relators/CTG`		`"John Smith"`

then it can be inferred that it is also true that

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/contributor`		`"John Smith"`

The "dumb-down" process utilises inferences such as this to derive (wherever possible) statements that reference the properties of the Dublin Core Metadata Element Set.

Example 1 : Contributor

The information that a named entity is a contributor to the content of a resource could be represented as follows:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/contributor`		`"John Smith"`

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/">

  <rdf:Description rdf:about="http://example.org/things/resource"
                   dc:contributor="John Smith" />

</rdf:RDF>

Example 1: RDF/XML

<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

  <head profile="http://dublincore.org/documents/dcq-html/">
    <link rel="schema.DC" href="http://purl.org/dc/elements/1.1/" />
    <meta name="DC.contributor" content="John Smith" />
  </head>

</html>

Example 1: XHTML

<?xml version="1.0"?>
<descriptionSet xmlns:dc="http://purl.org/dc/elements/1.1/">

  <description>
    <dc:contributor>John Smith</dc:contributor>
  </description>

<descriptionSet>

Example 1: DC-XML

Note: The XML format defined by the current guidelines for encoding DC metadata in XML [DC-XML] does not provide a mechanism for encoding a Resource URI.

Example 2: MARC Relator property is not subproperty of DC property

The information that a named entity is the owner of a resource could be represented as follows:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://www.loc.gov/loc.terms/relators/OWN`		`"John Smith"`

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:marcrel="http://www.loc.gov/loc.terms/relators/">

  <rdf:Description rdf:about="http://example.org/things/resource"
                   marcrel:OWN="John Smith" />

</rdf:RDF>

Example 2: RDF/XML

<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

  <head profile="http://dublincore.org/documents/dcq-html/">
    <link rel="schema.MARCREL" href="http://www.loc.gov/loc.terms/relators/" />
    <meta name="MARCREL.OWN" content="John Smith" />
  </head>

</html>

Example 2: XHTML

<?xml version="1.0"?>
<descriptionSet xmlns:marcrel="http://www.loc.gov/loc.terms/relators/">

  <description>
    <marcrel:OWN>John Smith</marcrel:OWN>
  </description>

<descriptionSet>

Example 2: DC-XML

As there is no assertion of a refinement relationship between the property marcrel:OWN and any other property, no inference can be made, and this statement would not be represented in a "dumbed-down" metadata description.

Example 3: MARC Relator property is subproperty of DC property

The information that a named entity is the illustrator of a resource could be represented as follows:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://www.loc.gov/loc.terms/relators/ILL`		`"John Smith"`

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:marcrel="http://www.loc.gov/loc.terms/relators/">

  <rdf:Description rdf:about="http://example.org/things/resource"
                   marcrel:ILL="John Smith" />

</rdf:RDF>

Example 3: RDF/XML

<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

  <head profile="http://dublincore.org/documents/dcq-html/">
    <link rel="schema.MARCREL" href="http://www.loc.gov/loc.terms/relators/" />
    <meta name="MARCREL.ILL" content="John Smith" />
  </head>

</html>

Example 3: XHTML

<?xml version="1.0"?>
<descriptionSet xmlns:marcrel="http://www.loc.gov/loc.terms/relators/">

  <description>
    <marcrel:ILL>John Smith</marcrel:ILL>
  </description>

<descriptionSet>

Example 3: DC-XML

As the property marcrel:ILL is declared to be a refinement of the property dc:contributor, the "dumb-down" process would generate the following metadata description:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/contributor`		`"John Smith"`

Example 4: Two different relationships between same two resources (1)

If the same entity is both an owner of a resource and a publisher of the resource, then that can be represented as two statements about the resource:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/publisher`		`"John Smith"`
`http://www.loc.gov/loc.terms/relators/OWN`		`"John Smith"`

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/"
         xmlns:marcrel="http://www.loc.gov/loc.terms/relators/">

  <rdf:Description rdf:about="http://example.org/things/resource"
                   dc:publisher="John Smith" marcrel:OWN="John Smith" />

</rdf:RDF>

Example 4: RDF/XML

<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

  <head profile="http://dublincore.org/documents/dcq-html/">
    <link rel="schema.DC" href="http://purl.org/dc/elements/1.1/" />
    <link rel="schema.MARCREL" href="http://www.loc.gov/loc.terms/relators/" />
    <meta name="DC.publisher" content="John Smith" />
    <meta name="MARCREL.OWN" content="John Smith" />
  </head>

</html>

Example 4: XHTML

<?xml version="1.0"?>
<descriptionSet xmlns:marcrel="http://www.loc.gov/loc.terms/relators/"
                xmlns:dc="http://purl.org/dc/elements/1.1/">

  <description>
    <dc:publisher>John Smith</dc:publisher>
    <marcrel:OWN>John Smith</marcrel:OWN>
  </description>

<descriptionSet>

Example 4: DC-XML

The "dumb-down" process would result in a description containing only a single statement:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/publisher`		`"John Smith"`

Example 5: Two different relationships between same two resources (2)

If the same entity is both an illustrator of a resource and a publisher of the resource, then that can be represented as two statements about the resource:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/publisher`		`"John Smith"`
`http://www.loc.gov/loc.terms/relators/ILL`		`"John Smith"`

<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/"
         xmlns:marcrel="http://www.loc.gov/loc.terms/relators/">

  <rdf:Description rdf:about="http://example.org/things/resource"
                   dc:publisher="John Smith" marcrel:ILL="John Smith" />

</rdf:RDF>

Example 5: RDF/XML

<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">

  <head profile="http://dublincore.org/documents/dcq-html/">
    <link rel="schema.DC" href="http://purl.org/dc/elements/1.1/" />
    <link rel="schema.MARCREL" href="http://www.loc.gov/loc.terms/relators/" />
    <meta name="DC.publisher" content="John Smith" />
    <meta name="MARCREL.ILL" content="John Smith" />
  </head>

</html>

Example 5: XHTML

<?xml version="1.0"?>
<descriptionSet xmlns:marcrel="http://www.loc.gov/loc.terms/relators/"
                xmlns:dc="http://purl.org/dc/elements/1.1/">

  <description>
    <dc:publisher>John Smith</dc:publisher>
    <marcrel:ILL>John Smith</marcrel:ILL>
  </description>

<descriptionSet>

Example 5: DC-XML

As the property marcrel:ILL is declared to be a refinement of the property dc:contributor, the "dumb-down" process would result in a description containing two statements:

Resource URI Statements

http://example.org/things/resource

Property URI	Value URI	Value String
`http://purl.org/dc/elements/1.1/publisher`		`"John Smith"`
`http://purl.org/dc/elements/1.1/contributor`		`"John Smith"`

Notes

[1] For the sake of brevity, in the text of this document, property URIs are represented by Qualified Names. Prefixes are assumed to be associated with Namespace Names as follows:

dc: http://purl.org/dc/elements/1.1/
dcterms: http://purl.org/dc/terms/
dcmitype: http://purl.org/dc/dcmitype/
marcrel: http://www.loc.gov/loc.terms/relators/
rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns#
rdfs: http://www.w3.org/2000/01/rdf-schema#
ex: http://example.org/things/

In the tabular representations of the DC metadata descriptions, the full URI is included.

References

[DCMIAM]
DCMI Abstract Model
http://dublincore.org/documents/abstract-model/

[DC-XML]
Guidelines for implementing Dublin Core in XML
http://dublincore.org/documents/dc-xml-guidelines/

Title:	MARC Relator Properties in Dublin Core Metadata
Creator:	Pete Johnston
Date Issued:	2005-12-07
Identifier:	http://www.ukoln.ac.uk/metadata/dcmi/marcrel-ex/2005-12-07/
Replaces:	http://www.ukoln.ac.uk/metadata/dcmi/marcrel-ex/2005-12-06/
Is Replaced By:	Not applicable
Latest Version:	http://www.ukoln.ac.uk/metadata/dcmi/marcrel-ex/
Description of Document:	This document provides some examples of the use of the MARC Relator properties in Dublin Core metadata descriptions.