DC8 Ottawa, October 4-6, 2000

Rachel HeeryUKOLN, University of Bath

r.heery@ukoln.ac.ukhttp://www.ukoln.ac.uk

Application Profiles:managing metadata schemas

DC8 Ottawa, October 4-6, 2000

What implementors are doing ….What implementors are doing ….

• Formulating schema• identifying existing schemas where useful

• Adding variety of ‘local extensions’ to standard schemas for specific requirements• adding local elements• refining definitions

• Establishing local good practice• formulating rules for content

DC8 Ottawa, October 4-6, 2000

Examples of emerging schemasExamples of emerging schemas• DC-educationhttp://purl.org/dc/document/wd/education-20000430.htm

• describing educational resources• Jon Mason (EdNA) and Stuart Sutton (GEM)• users, duration, learning processes, standards,

quality• RSLP collection descriptionhttp://www.ukoln.ac.uk/metadata/rslp/schema/

• describing newly digitised special collections catalogues

• Andy Powell (UKOLN)• collection policy, responsibility, location

DC8 Ottawa, October 4-6, 2000

DC-Education proposed schemaDC-Education proposed schema

• Various DC elements and recommended qualifiers

• DC-education extensions– audience mediator– standard identifier, version

• IEEE LOM IMS elements– TypicalLearningTime, InteractivityType,

InteractivityLevel

DC8 Ottawa, October 4-6, 2000

RSLP Collection Description schema RSLP Collection Description schema

• dc:title The name of the collection • dc: identifier A formal identifier for the collection • dc:description A description of the collection • cld:strength An indication (free text or

formalised) of the strength(s) of the collection • cld:accessControl A statement of any access

restrictions placed on the collection including allowed users, charges etc

• …….• …...

DC8 Ottawa, October 4-6, 2000

Implementors’ requirementsImplementors’ requirements

• How can implementors be helped to find out about local usage • Discovering information about schemas in

use.

• How can implementors combine element sets from different namespaces • Establishing context for Dublin Core.

Answers will inform DC collaboration with other metadata initiatives

DC8 Ottawa, October 4-6, 2000

Good metadata management requirementsGood metadata management requirements

• Inter-working systems• Disclosure of semantics• Alignment of metadata

• Disclosure• What schemas exist?• Is this schema current?• How is it used?

• Economies of scale• Re-use of effort

• -

DC8 Ottawa, October 4-6, 2000

Application profilesApplication profiles

DC8 Ottawa, October 4-6, 2000

Types of metadata schemaTypes of metadata schema

• Namespace schemas• International standards • Locally defined schemas, domain specific

schemas

• Application profiles• Combinations, subsets, variants of

namespace schema

DC8 Ottawa, October 4-6, 2000

What is an application profile?What is an application profile?

Schema consisting of data elements drawn from one or more namespaces optimised for a particular local application

– Draws on existing namespaces

– Introduces no new data elements

– Can specify permitted schemes and values

– Can refine definitions

DC8 Ottawa, October 4-6, 2000

DC-Education proposed schemaDC-Education proposed schema

• Various DC elements and recommended qualifiers

• DC-education extensions– audience mediator– standard identifier, version

• IEEE LOM IMS elements– TypicalLearningTime, InteractivityType,

InteractivityLevel

DC8 Ottawa, October 4-6, 2000

RSLP Collection Description schema RSLP Collection Description schema

• dc:title The name of the collection • dc: identifier A formal identifier for the collection • dc:description A description of the collection • cld:strength An indication (free text or

formalised) of the strength(s) of the collection • cld:accessControl A statement of any access

restrictions placed on the collection including allowed users, charges etc

• …….• …...

DC8 Ottawa, October 4-6, 2000

Syntax issues: how to capture Syntax issues: how to capture expression of application profile?expression of application profile?

Within metadata instance?• HTML• XML/RDF• XML

Within schema definition?• XML Schemas• RDF Schemas

Characteristics to be expressed?

• Rules for content• Alternative definitions• Subsets• Mixing elements from

different sets

…and avoid complexity

DC8 Ottawa, October 4-6, 2000

IssuesIssues• Conformance

• what is a valid IEEE LOM record?

• Avoiding overlap and ambiguity

• What is the distinction between schemas, namespace and vocabularies

DC8 Ottawa, October 4-6, 2000

Influence of syntaxInfluence of syntax

RDF can be very expressive in its assertions within an instance of metadata..

• Ensure expressions of application profiles can be made independent of RDF

• How much expression must go into the schema language, how much into the metadata record?

DC8 Ottawa, October 4-6, 2000

Deal with classesDeal with classes

• Metadata can be complex• Can describe different classes

• Collection Descriptions deal with people, items, locations

• Does this mean separate schemas per class? Or more richly structured schema?

• Same solution for schemas and application profiles!

DC8 Ottawa, October 4-6, 2000

Where do we go from here?Where do we go from here?

DC8 Ottawa, October 4-6, 2000

Publishing application profilesPublishing application profiles

• Why?• To inform and promote• To provide authoritative version• To facilitate inter-working• To align with other schemas

• How?• Facilitate schema registration • Metadata registries

DC8 Ottawa, October 4-6, 2000

Metadata registry activityMetadata registry activity

• DC Registry working group

• Schemas Workshop, Bonn, November 23-24

http://www.schemas-forum.org/

DC8 Ottawa, October 4-6, 2000

Change of emphasisChange of emphasis

…..not new functionality

DC8 Ottawa, October 4-6, 2000

ReferencesReferencesDESIRE registryhttp://desire.ukoln.ac.uk/registry/Dublin Core Registry discussion listhttp://www.mailbase.ac.uk/lists/dc-registry/IEEE Learning Object Metadata Schemehttp://ltsc.ieee.org/doc/wg12/scheme.htmlBIBLINKCorehttp://hosted.ukoln.ac.uk/biblink/wp8/fs/bc-semantics.htmlRDF Schema Specificaionhttp://www.w3.org/TR/2000/CR-rdf-schema-20000327/SCHEMAShttp://www.schemas-forum.org/Namespaces in XMLhttp://www.w3.org/TR/REC-xml-names