An Introduction to the DCMI Abstract Model - PowerPoint PPT Presentation

An introduction to the dcmi abstract model l.jpg
Download
1 / 43

An Introduction to the DCMI Abstract Model. JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester. An Introduction to the DCMI Abstract Model. Context & Motivation: Why the DCAM? The DCMI Abstract Model The DCAM & “DC application profiles” The DCAM & DCMI “encoding guidelines”

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

An Introduction to the DCMI Abstract Model

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


An introduction to the dcmi abstract model l.jpg

An Introduction to the DCMI Abstract Model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


An introduction to the dcmi abstract model2 l.jpg

An Introduction to the DCMI Abstract Model

  • Context & Motivation: Why the DCAM?

  • The DCMI Abstract Model

  • The DCAM & “DC application profiles”

  • The DCAM & DCMI “encoding guidelines”

  • Dublin Core in 2007

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide3 l.jpg

Context & Motivation: Why the DCAM?

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Why dcam context motivation l.jpg

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

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Why dcam context motivation5 l.jpg

Why DCAM? Context & Motivation

  • Work on DCAM from mid-2003, initiated by Andy Powell

  • DCMI Recommendation, 2005-03-07

  • Feedback from

    • DCMI Usage Board

    • DCMI working groups, designers of DCAPs

    • Implementers of DCAPs

    • Implementers of metadata registries

    • Developers/implementers of related specs

    • Semantic Web community

    • Researchers

  • Revision currently in progress

    • Proposed Rec for Public Comment, 2007-02-05

    • Proposed Rec for Public Comment, 2007-04-02

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide6 l.jpg

The DCMI Abstract Model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide7 l.jpg

Proposed Recommendation

http://dublincore.org/documents/2007/04/02/abstract-model/


The dcmi abstract model l.jpg

The DCMI 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

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


The dcmi abstract model9 l.jpg

The DCMI Abstract Model

  • DCAM describes

    • Components and constructs that make up an information structure (“DC description set”)

    • How that information structure is to be interpreted

  • DCAM does not describe how to represent DC description set in concrete form

  • DCAM describes various types of metadata term, but does not specify the use of any fixed set of terms

  • Made up of three related “information models”

    • Resource model

    • Description set model

    • Vocabulary model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dcam resource model l.jpg

DCAM Resource Model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dcam resource model11 l.jpg

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

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dcam description set model l.jpg

DCAM Description Set Model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dcam description set model13 l.jpg

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

      • identifiesdescribed resource

    • one or more statements

  • a statement is made up of

    • exactly one property URI

      • identifiesproperty

    • exactly one value surrogate

  • a value surrogate is either a literal value surrogate or a non-literal value surrogate

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide14 l.jpg

Description Set

Description

Description

Property URI

Statement

Statement

Statement

Literal Value Surrogate

Property URI

Non-Literal Value Surrogate

Non-Literal Value Surrogate

Property URI

Resource URI

Resource URI


Dcam description set model15 l.jpg

DCAM Description Set Model

  • a literal value surrogate is made up of

    • exactly one value string

      • encodesvalue

  • a non-literal value surrogate is made up of

    • zero or one value URIs

      • identifiesvalue

    • zero or one vocabulary encoding scheme URI

      • identifies a set of which the value is a member

    • zero or more value strings

      • representsvalue

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide16 l.jpg

Description Set

Description

Resource URI

Description

Property URI

Statement

Statement

Literal Value Surrogate

Statement

Non-Literal Value Surrogate

Property URI

Value URI

Vocab Enc Scheme URI

Value string

Value string

Non-Literal Value Surrogate

Resource URI

Property URI

Value URI

Value string


Dcam description set model17 l.jpg

DCAM Description Set Model

  • 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

  • Not going to say more about SES today!

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide18 l.jpg

Description Set

Description

Resource URI

Description

Value URI

Property URI

Statement

Statement

Literal Value Surrogate

Statement

Non-Literal Value Surrogate

Property URI

Value URI

Vocab Enc Scheme URI

Value string

Language

Value string

Non-Literal Value Surrogate

Resource URI

Property URI

Value string

Language

Syntax Enc Scheme URI


Dcam description set model19 l.jpg

DCAM Description Set Model

  • a value may be described by another description

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide20 l.jpg

Description Set

Description

Resource URI

Description

Value URI

Property URI

Statement

Statement

Literal Value Surrogate

Statement

Non-Literal Value Surrogate

Property URI

Value URI

Vocab Enc Scheme URI

Value string

Language

Value string

Syntax Enc Scheme URI

Non-Literal Value Surrogate

Resource URI

Property URI

Value string

Language


Slide21 l.jpg

Description Set

Description

Resource URI

Description

Non-Literal Value Surrogate

Property URI

Statement

Statement

Literal Value Surrogate

Statement

Non-Literal Value Surrogate

Property URI

Value URI

Vocab Enc Scheme URI

Value string

Language

Value string

Syntax Enc Scheme URI

Property URI

Value string

Language


Slide22 l.jpg

Some example description sets

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide23 l.jpg

Description Set

Statement

Example 1: Single description containing one statement with non-literal value surrogate

Description

Resource URI

Non-Literal Value Surrogate

Property URI

Value URI


Slide24 l.jpg

Example 1: Single description containing one statement with non-literal value surrogate

Description Set

Description

<http://dublincore.org/documents/abstract-model/>

Statement

Non-Literal Value Surrogate

<http://purl.org/dc/terms/publisher>

Property URI

Value URI

<http://example.org/org/DCMI>

@prefix dcterms <http://purl.org/dc/terms/> .

DescriptionSet (

Description (

ResourceURI ( <http://dublincore.org/documents/abstract-model/> )

Statement (

PropertyURI ( dcterms:publisher )

ValueURI (<http://example.org/org/DCMI> )

)

)

)


Slide25 l.jpg

Statement

Value URI

Vocab Enc Scheme URI

Value string

Value string

Example 2: Single description containing two statements with non-literal value surrogates

Description Set

Description

Resource URI

Non-Literal Value Surrogate

Property URI

Value URI

Statement

Non-Literal Value Surrogate

Property URI

Language

Language


Slide26 l.jpg

Statement

Example 2: Single description containing two statements with non-literal value surrogates

Description Set

Description

<http://dublincore.org/documents/abstract-model/>

Non-Literal Value Surrogate

<http://purl.org/dc/terms/publisher>

Property URI

Value URI

<http://example.org/org/DCMI>

Statement

Non-Literal Value Surrogate

<http:/purl.org/dc/terms/subject>

<http://example.org/org/mySH/h123>

Value URI

Property URI

Vocab Enc Scheme URI

<http://example.org/terms/mySH>

“Metadata”

en

Value String

"Métadonnées"

fr

Value String


Slide27 l.jpg

Example 2: Single description containing two statements with non-literal value surrogates

@prefix dcterms <http://purl.org/dc/terms/> .

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 ) )

)

)

)


Slide28 l.jpg

Statement

Statement

Example 3: Two descriptions, statements with non-literal value surrogates & literal value surrogates

Description Set

Description

Resource URI

Non-Literal Value Surrogate

Property URI

Value URI

Statement

Non-Literal Value Surrogate

Property URI

Value URI

Vocab Enc Scheme URI

Value string

Language

Value string

Language

Description

Resource URI

Literal Value Surrogate

Property URI

Value string

Language


Slide29 l.jpg

Statement

Statement

Example 3: Two descriptions, statements with non-literal value surrogates & literal value surrogates

Description Set

Description

<http://dublincore.org/documents/abstract-model/>

Non-Literal Value Surrogate

<http://purl.org/dc/terms/publisher>

Property URI

Value URI

<http://example.org/org/DCMI>

Statement

Non-Literal Value Surrogate

<http:/purl.org/dc/terms/subject>

<http://example.org/org/mySH/h123>

Value URI

Property URI

Vocab Enc Scheme URI

<http://example.org/terms/mySH>

“Metadata”

en

Value String

"Métadonnées"

fr

Value String

Description

<http://example.org/org/DCMI>

Literal Value Surrogate

<http://xmlns.com/foaf/0.1/name>

“Dublin Core Metadata Initiative”

en

Value String

Property URI


Slide30 l.jpg

@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 vocabulary model l.jpg

DCAM Vocabulary Model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dcam vocabulary model32 l.jpg

DCAM Vocabulary Model

  • a vocabulary is a set of terms (property, class, vocabulary encoding scheme, syntax encoding scheme)

  • a resource may be an instance of one or more classes

  • a resource may be a member of one or more vocabulary encoding schemes

  • a property may have a range relationship with one or more classes

  • a property may have a domain relationship with one or more classes

  • a property may have a subproperty relationship with one or more properties

  • a class may have a subclass relationship with one or more classes

  • =~ RDF Schema

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Current recent issues l.jpg

Current/recent issues

  • DCAM & RDF

    • Mapping to RDF graphs specified by Expressing DC metadata using RDFhttp://dublincore.org/documents/2007/04/02/dc-rdf

  • Clarifying distinction between “things” & “strings”

  • DCAM as abstract syntax for RDF v DCAM as “domain (metadata) model”

    • Reflects DCMI community’s view of metadata

    • Uses concepts developed by that community

    • Formulated so as to be compatible with RDF/RDFS

  • Possibly require further note(s) on merging, inferencing

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide34 l.jpg

The DCAM & “DC application profiles”

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


The dcam dc application profiles l.jpg

The DCAM & “DC application profiles”

  • 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

    • Currently DCMI has no formal model for DCAP

  • DCAP as “description set profile”

    • Specification of how to construct description sets to meet some set of requirements

  • Definition of DCAP based on

    • functional requirements

    • domain model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide36 l.jpg

The DCAM & “encoding guidelines”

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


The dcam encoding guidelines l.jpg

The DCAM & “encoding guidelines”

  • DCAM is independent of any concrete syntax

  • For transfer between applications, descriptions must be encoded as digital objects (records)

  • DCMI “Encoding Guidelines” describe

    • how description set is serialised/encoded as a record using a format

    • how records conforming to format are decoded/interpreted as description sets

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide38 l.jpg

System A

System B

Construct usingDCAM & DCAP

Interpret usingDCAM

DC DescriptionSet

DC DescriptionSet

Encode

Decode

DC-XMLInstance

DC-XMLInstance

<?xml version="1.0"?><dcx:descriptionSet>


The dcam encoding guidelines39 l.jpg

The DCAM & “encoding guidelines”

  • Current DCMI “Encoding Guidelines” specs

    • Pre-date development of DCAM

    • Use earlier, simpler “DC abstract models”

    • Not fully compatible with DCAM description set model

  • Currently, no DCMI recommendation for machine-readable format for description set model

  • Updating of specs in progress (2007)

    • DC-XML

    • DC in X/HTML link/meta elements

  • Meanwhile, some formats defined outside of DCMI

    • e.g. Eprints DC-XML

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Slide40 l.jpg

Some thoughts on Dublin Core in 2007

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dublin core in 2007 l.jpg

Dublin Core in 2007

  • Not just “a set of 15 elements”

  • Not even a set of 15 elements, +70-odd other terms (element refinements, vocabulary encoding schemes, syntax encoding schemes, classes)

  • Not just “Simple Dublin Core” and “Qualified Dublin Core”

  • Not limited to “simple” “flat” “atomic” descriptions

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


Dublin core in 200742 l.jpg

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

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


An introduction to the dcmi abstract model43 l.jpg

An Introduction to the DCMI Abstract Model

JISC CETIS Metadata & Digital Repositories SIG meeting, Manchester


  • Login