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Vocabulary Management Task Force. Tom Baker Semantic Web Best Practices and Deployment Working Group W3C Technical Plenary Boston, 2005-03-03. Members. Tom Baker Libby Miller Dan Brickley Alistair Miles Alan Rector Aldo Gangemi Bernard Vatant Ralph Swick
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Vocabulary ManagementTask Force Tom Baker Semantic Web Best Practices and Deployment Working Group W3C Technical Plenary Boston, 2005-03-03
Members • Tom Baker • Libby Miller • Dan Brickley • Alistair Miles • Alan Rector • Aldo Gangemi • Bernard Vatant • Ralph Swick • Jim Hendler (for Introduction)
“Managing a Vocabulary forthe Semantic Web” • Scope and objectives • Basic principles for maintaining RDF vocabularies in a Semantic-Web-friendly way. • Vocabularies: • That can support processes of referencing, repurposing, recombining, merging data from a diversity of sources • That are evolvable • That are extensible and mixable with other SW vocabularies • That are declared processibly
Outline -- Introduction • What it means to use a vocabulary in a “Semantic Web” environment • Focus on a few “exemplary” vocabularies: • DC • SKOS • FOAF • PRISM • W3C Points of Reference: • TAG Architecture of the World-Wide Web • TBL on Cool URIs and Web Design issues (1998+) • OASIS Published Subjects? (see below)
Outline -- Terminology • Minimal jargon, briefly defined, for bootstrapping…: • Term: A named concept. • Vocabulary: A set of terms. • URI Reference (now to be called just “URI”!) • Vocabulary Owner: The maintainer of a term set. • Versioning: The identification of changes to a term or vocabulary. • … • Agreeing on terminology “for the purpose of this note” • See below for messy subtleties…
Outline – Principles ofGood Practice • Identify terms with URIs! • Articulate your maintenance policies • Identify versions • Provide documentation (for people) • Publish a formal schema • Not just for consumption by applications, but for social reasons • Implies an ontological commitment to RDF data model
Outline – Evolving Practice --1…or Bleeding Edge? • Dereferencing URIs • Choice of schema language • Plain RDF/S? SKOS or OWL (ontological commitment)? • Reusing, adapting, mixing vocabularies • E.g., Dublin Core Application Profiles • Coining new terms (e.g., see DCMI guidelines) • Slash versus hash? • Vocabulary Ownership • “Social meaning” (Jeremy?)
Outline – Evolving Practice -- 2…or Bleeding Edge? • Work-flow for maintaining vocabularies • One extreme: DCMI XSLT scripts. Other: big ontologies • The notion of “namespace” (vs “vocabulary”) • What is a “term”? • Thesaurus world: lexical versus conceptual view • DCMI: Properties/classes identified by URIs • Some RDF specs (e.g., SPARQL): “the URIs themselves”
Dublin Core Best Practice • DCMI Namespace Policy • http://dublincore.org/documents/dcmi-namespace/ • DCMI Abstract Model • http://dublincore.org/documents/abstract-model/ • Guidelines for assigning identifiers to metadata terms • http://dublincore.org/documents/term-identifier-guidelines/ • XML, RDF, and DCAPs [differences btw. XML elements and RDF properties] • http://www.ukoln.ac.uk/metadata/dcmi/dc-elem-prop/ • DCMI Policy for names of properties and classes • http://dublincore.org/documents/naming-policy • DC Application Profiles in RDF • ftp://ftp.cenorm.be/public/ws-mmi-dc/mmidc132.pdf • DCMI Mixing and Matching FAQ [draft] • http://www.ukoln.ac.uk/metadata/dcmi/mixing-matching-faq/ • Versioning of terms • ftp://ftp.cenorm.be/public/ws-mmi-dc/mmidc148.pdf • Workflow for generating Web documentation and RDF schemas of DCMI terms • On Web soon
OASIS Published Subjects? • Steve Pepper talk – RDF/TF rapprochement • Illustrate best-practice principles? • Or separate discussion of its own?
Other vocabularies? Ontologies? • WordNet? FAO Thesaurus? • Vocabularies online but “pre-Semantic-Web” (no URIs…) • SNOMED-CT, HL7, NCI Metathesaurus, Gene Ontology, Unified Medical Language • We want to encourage online access as first step
Next step – VM Note • VM Note of 8-12 pages • If we agree on scope and outline here: achievable fairly quickly! • Presupposes attention of a core of Task Force members • Fill in the blanks… • Telecons scheduled every… • First Public Working Draft by…
Next steps after that… • Harmonization SKOS – DC – FOAF • Started with review of PORT deliverables • Managed URIs / definitions for term attributes (“Status”) • Proposals for DCMI or W3C namespaces? • Shared formalisms for declaring vocabularies • Note describing versioning method, RDF schema details, set of attributes • Shared process model…?? • Endorsement model! • LoC says: “marc:translator rdfs:subPropertyOf dc:contributor” • DCMI says: “We endorse the above assertion!”