Dublin Core application profiles in context
Thomas Baker22 October 2009
Knowledge Organization Systems:Managing to the Future
A joint CENDI/NKOS WorkshopNational Agricultural Library
Beltsville, MD
2
RDF – a grammar for Web links
ResourcePropertyy
http://dublincore.org/workshops/dc6/pp/miller-datamodel.ppt, 1998
ResourceResourcePropertyy
Resource
ResourcePropertyy
ResourcePropertyy Literal (descriptive
text or numerical data)
“Introduction to RDF” in one slide…!
“Property” means “is related to”.
Interoperability Levelsfor Dublin Core metadata
1: Informal interoperabilityShared vocabularies defined in natural language
2: Semantic interoperabilityShared vocabularies based on formal semantics
3: Description Set syntactic interoperabilityShared formal vocabularies in exchangeable records
4: Description Set Profile InteroperabilityShared formal vocabularies and constraints in records
http://dublincore.org/documents/interoperability-levels/
Shared (natural-language) definitions
Shared formal-semantic model
Shared model for “records”
Shared validatable constraints
Open- and closed-world
Shared (natural-language) definitionsData in silos. “Intra-operability” within silos.
Shared formal-semantic model“Open-world” data.
Shared model for “records”Open-world data captured in manageable records.
Shared constraintsOpen-world data optimized for specific environments.
Supporting technologies
Shared (natural-language) definitionsClosed systems. Proprietary systems. Web of APIs.DC-XML/2003 and other early DCMI specs.
Shared formal-semantic modelLinked data. RDF data. Extracted triples.DC-RDF. DC-HTML. RDFa!
Shared model for “records”DCMI Abstract Model. DC-DS-XML.SPARQL Named Graphs.
Shared constraintsDCMI Description Set Profile.SPARQL Query Patterns.
Deployed base
Shared (natural-language) definitions
Shared formal-semantic modelShared “records”
Shared constraints
Rate of growth
Shared (natural-language) definitions
Shared formal-semantic modelShared “records”
Shared constraints
Which level do you require?
Shared (natural-language) definitionsPro: Easier to deploy. Validatable records.Contra: Closed-world. Interoperability by (thousands of) ad-hoc agreements.
Shared formal-semantic modelPro: Easier to integrate and migrate data.Contra: Harder to design, less tools.
Shared model for “records”Pro: Provenance. Trust.Contra: Lack of mature, deployed models.
Shared constraintsPro: Validation. Quality.Contra: It is “constraining”…
Level-1 apps interoperate with shared or mapped schemas
Schema A Schema B Schema C
sameas
mappedto
Good level-2 Application Profiles create good triples
Profile A Profile B Profile C
Good triples can be merged coherently
Profile A Profile B Profile C
Applications come and go…
Profile A Profile B Profile C
The data remains
Data quality is independent of profiles used to create it
SPARQL Endpoint
Queries
