Brian Kelly UK Web Focus UKOLN University of Bath BA2 7AY [email protected]
Rachel Heery UKOLN, University of Bath [email protected] ukoln.ac.uk
description
Transcript of Rachel Heery UKOLN, University of Bath [email protected] ukoln.ac.uk
DC8 Ottawa, October 4-6, 2000
Rachel HeeryUKOLN, University of Bath
[email protected]://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/
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Change of emphasisChange of emphasis
…..not new functionality
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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