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

tbaker@tbaker.de