1. Vocabulary Management Task Force Tom Baker Semantic Web Best Practices and Deployment Working Group W3C Technical Plenary Boston, 2005-03-03

2. Members Tom Baker Libby Miller Dan Brickley Alistair Miles Alan Rector Aldo Gangemi Bernard Vatant Ralph Swick Jim Hendler (for Introduction)

3. “Managing a Vocabulary for the 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

4. 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)

5. 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…

6. Outline – Principles of Good 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

7. 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?)

8. 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”

9. Dublin Core Best Practice DCMI Namespace Policy –http://dublincore.org/documents/dcmi-namespace/http://dublincore.org/documents/dcmi-namespace/ DCMI Abstract Model –http://dublincore.org/documents/abstract-model/http://dublincore.org/documents/abstract-model/ Guidelines for assigning identifiers to metadata terms –http://dublincore.org/documents/term-identifier-guidelines/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/http://www.ukoln.ac.uk/metadata/dcmi/dc-elem-prop/ DCMI Policy for names of properties and classes –http://dublincore.org/documents/naming-policyhttp://dublincore.org/documents/naming-policy DC Application Profiles in RDF –ftp://ftp.cenorm.be/public/ws-mmi-dc/mmidc132.pdfftp://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/http://www.ukoln.ac.uk/metadata/dcmi/mixing-matching-faq/ Versioning of terms –ftp://ftp.cenorm.be/public/ws-mmi-dc/mmidc148.pdfftp://ftp.cenorm.be/public/ws-mmi-dc/mmidc148.pdf Workflow for generating Web documentation and RDF schemas of DCMI terms –On Web soon

10. OASIS Published Subjects? Steve Pepper talk – RDF/TF rapprochement Illustrate best-practice principles? Or separate discussion of its own?

11. 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

12. 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…

13. 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!”