Dublin Core, the DCMI Abstract Model & DC Application Profiles

Dublin Core, the DCMI Abstract Model & DC Application Profiles Images DC Application Profile WG meeting, London

Dublin Core, the DCMI Abstract Model & DC Application Profiles
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An Introduction to the DCMI Abstract Model
Why the DCAM?
The DCMI Abstract Model
The DCAM & “DC application profiles”
Dublin Core in 2007

Why DCAM? Context & Motivation
Some issues for DCMI c.2003
Metadata vocabularies
… but what is a DC “element”?
Encoding guidelines
… but what are we “encoding”?
DC application profiles
… but what “terms” can we “use”?
“ Simple” and “Qualified” DC
Grammatical Principles
DC & the Resource Description Framework
Work on DCAM from mid-2003, initiated by Andy Powell
Initial Version, DCMI Recommendation, 2005-03-07
Second Version, DCMI Recommendation, 2007-06-04
http://dublincore.org/documents/2007/06/04/abstract-model/

DCAM concerned with description of resources
DCAM adopts Web Architecture/RFC3986 definition of resource
the term "resource" is used in a general sense for whatever might be identified by a URI. Familiar examples include an electronic document, an image, a source of information with consistent purpose (e.g., "today's weather report for Los Angeles"), a service (e.g., an HTTP to SMS gateway), a collection of other resources, and so on.
A resource is not necessarily accessible via the Internet; e.g., human beings, corporations, and bound books in a library can also be resources.
Likewise, abstract concepts can be resources, such as the operators and operands of a mathematical equation, the types of a relationship (e.g., "parent" or "employee"), or numeric values (e.g., zero, one, and infinity).
RFC3986 URI Syntax

DCAM describes
Components and constructs that make up an information structure (“DC description set”)
How that information structure is to be interpreted
Made up of three related “information models”
Resource model
Description set model
Vocabulary model
In this presentation, focus on description set model

DCAM does not describe how to represent DC description set in concrete form
“ Encoding guidelines”
Updating of specs in progress (2007)
DC-XML
DC in X/HTML link/meta elements
Some formats defined outside of DCMI, e.g. Eprints DC-XML
DCAM describes various types of metadata term, but does not specify the use of any fixed set of terms
Metadata vocabularies
Define/owned by DCMI or by other agencies
DCAM & RDF
Mapping of description sets to RDF graph specified by Expressing DC metadata using RDF http://dublincore.org/documents/2007/06/04/dc-rdf

DCAM Resource Model

DCAM Resource Model
The “view of the world” on which DC metadata is based
a described resource is described using one or more property-value pairs
a property-value pair is made up of
exactly one property and
exactly one value
a value is a resource
a value is either a literal value or a non-literal value
i.e. similar to RDF model of binary relations between resources; entity-relational model

DCAM Description Set Model

The structure of DC metadata
Uses URIs to refer to resources & metadata terms (like RDF)
a description set is made up of one or more descriptions , each of which describes one resource
a description is made up of
zero or one described resource URI
identifies described resource
one or more statements
a statement is made up of
exactly one property URI
identifies property
exactly one value surrogate
a value surrogate is either a literal value surrogate or a non-literal value surrogate

Resource URI Resource URI Description Set Description Statement Property URI Literal Value Surrogate Description Statement Property URI Non-Literal Value Surrogate Statement Property URI Non-Literal Value Surrogate

a literal value surrogate is made up of
exactly one value string
encodes value
a non-literal value surrogate is made up of
zero or one value URIs
identifies value
zero or one vocabulary encoding scheme URI
identifies a set of which the value is a member
zero or more value strings
represents value
a value string is either a plain value string or a typed value string
a plain value string may have an associated value string language
a typed value string is associated with a syntax encoding scheme URI

Value URI Description Set Description Statement Property URI Resource URI Literal Value Surrogate Description Statement Property URI Resource URI Non-Literal Value Surrogate Statement Property URI Non-Literal Value Surrogate Vocab Enc Scheme URI Value URI Value string Value string Syntax Enc Scheme URI Language Value string Language

a value may be described by another description

Description Set Description Statement Property URI Resource URI Literal Value Surrogate Description Statement Property URI Resource URI Non-Literal Value Surrogate Statement Property URI Non-Literal Value Surrogate Value URI Vocab Enc Scheme URI Value URI Value string Value string Value string Syntax Enc Scheme URI Language Language

Description Set Description Statement Property URI Literal Value Surrogate Description Statement Property URI Resource URI Non-Literal Value Surrogate Statement Property URI Non-Literal Value Surrogate Vocab Enc Scheme URI Value URI Value string Value string Value string Syntax Enc Scheme URI Language Language

Description Set Description Property URI Resource URI Example: Description set with two descriptions, statements with non-literal value surrogates & literal value surrogates Statement Property URI Non-Literal Value Surrogate Non-Literal Value Surrogate Vocab Enc Scheme URI Value URI Value string Value string Value URI Language Language Description Resource URI Property URI Literal Value Surrogate Value string Language Statement Statement

Description Set Description Statement <http:/purl.org/dc/terms/subject> Non-Literal Value Surrogate Non-Literal Value Surrogate <http://example.org/terms/mySH> “ Metadata” "Métadonnées" en fr <http://purl.org/dc/terms/publisher> <http://dublincore.org/documents/abstract-model/> <http://example.org/org/DCMI> Property URI Value URI <http://example.org/org/mySH/h123> Value URI Property URI Vocab Enc Scheme URI Value String Value String Description <http://example.org/org/DCMI> <http://xmlns.com/foaf/ 0.1/name> Literal Value Surrogate “ Dublin Core Metadata Initiative” en Value String Property URI Example: Description set with two descriptions, statements with non-literal value surrogates & literal value surrogates Statement Statement

@prefix dcterms <http://purl.org/dc/terms/> . @prefix foaf <http://xmlns.com/foaf/0.1/> . DescriptionSet ( Description ( ResourceURI ( <http://dublincore.org/documents/abstract-model/> ) Statement ( PropertyURI ( dcterms:publisher ) ValueURI (<http://example.org/org/DCMI> ) ) Statement ( PropertyURI ( dcterms:subject ) ValueURI (<http://example.org/mySH/h123> ) VocabEncSchemeURI (<http://example.org/terms/mySH> ) ValueString ( “Metadata” Language (en ) ) ValueString ( "Métadonnées" Language (fr ) ) ) ) Description ( ResourceURI ( <http://example.org/org/DCMI> ) Statement ( PropertyURI ( foaf:name ) LiteralValueString ( “Dublin Core Metadata Initiative” Language (en) ) ) ) )

DCAM does not specify the set of terms referenced in a description set
Notion of “DC application profile” widely used within DCMI and by DC implementers
Typically annotated lists of terms used in DC metadata so as to meet some domain/community requirements
Terms defined by DCMI or by other agencies
Specification of how to construct description sets (descriptions, statements) to serve some purpose
Based on
functional requirements
domain model

DCMI Description Set Profile (DSP)
A way of describing structural constraints on a description set
the resources that may be described by descriptions in the description set
the properties that may be used in statements
the ways a value surrogate may be given
Description templates, statement templates
Model & XML Syntax for DSP
Working draft by Mikael Nilsson ( Royal Institute of Technology, Sweden)
http://dublincore.org/architecturewiki/DescriptionSetProfile
Wiki Syntax for DSP
Working draft by Fredrik Enoksson ( Royal Institute of Technology, Sweden)
http:// dublincore.org/architecturewiki/DSPWikiSyntax

What is a DC Application Profile?
A DCAM-conformant Application Profile (“DC Application Profile”) is packet of documentation which consists of:
Functional requirements (desirable)
Domain model (mandatory)
Description Set Profile (DSP) (mandatory)
Usage guidelines (optional)
Encoding syntax guidelines (optional)

Foundation standards Domain standards Application Profile The “Singapore Framework”

Dublin Core in 2007

Dublin Core in 2007
a framework (the DCAM)
which describes how to use certain types of terms
... to make statements ...
... that form descriptions (of resources)
… that can be grouped together as description sets
a set of specifications for encoding description sets using various formats
a managed vocabulary of widely useful terms
which can be referenced in statements
support for defining additional vocabularies of terms
which can be referenced in statements
support for defining DC application profiles
which describe how to construct description sets for some particular set of requirements
extensibility, modularity, compatibility with Semantic Web

Dublin Core, the DCMI Abstract Model & DC Application Profiles Images DC Application Profile WG meeting, London

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Dublin Core, the DCMI Abstract Model & DC Application Profiles

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Dublin Core, the DCMI Abstract Model & DC Application Profiles Presentation Transcript