◆ Semantic Web Catalogue

Problem thread

One vocabulary or many

Should everyone share one ontology, reuse a few common vocabularies, or map between many local ones?

issue
vocabulary
also governance
status
open
steps
9, 1984–2016
threads
all problem threads

Cyc aimed at one comprehensive ontology for everything. The Web took smaller steps: a handful of shared vocabularies such as Dublin Core and FOAF, field-wide efforts like the Gene Ontology and the OBO Foundry, and ways to map one scheme to another when agreement fails. Schema.org became the one vocabulary most web pages use, while catalogues like LOV help publishers find and reuse hundreds of others.

Lineage

  1. 1984
    proposes project ★ seminal
    Cyc

    One comprehensive ontology and knowledge base spanning the basic concepts and rules of how the world works. [src]

  2. Mar 1995
    proposes standard ★ seminal
    Dublin Core

    A small shared set of metadata elements, agreed at an OCLC and NCSA workshop in Dublin, Ohio in March 1995. [src]

  3. 1998
    proposes project ★ seminal
    Gene Ontology

    One field agrees its terms: an ontology of gene and gene-product functions shared across the fly, mouse and yeast genome projects, and later across biology. [src1][src2]

  4. 2000
    proposes standard ★ seminal
    FOAF

    A community vocabulary for describing people, their online accounts and who they know, one of the first widely reused on the Semantic Web. [src]

  5. 2007
    workaround writing
    Ontology Matching

    When people will not share one ontology, find the correspondences between theirs: a survey and classification of ontology matching techniques. [src1][src2]

  6. 2007
    proposes project
    OBO Foundry

    Shared principles for biomedical ontologies: a common formal language, permanent identifiers, reuse of existing relations, and collaborative development. [src]

  7. 18 Aug 2009
    workaround standard ★ seminal
    SKOS

    Lets existing thesauri and classifications be published as they are, with mapping properties that state alignment links between concepts in different schemes. [src]

  8. 2 Jun 2011
    settles standard ★ seminal
    Schema.org

    For web pages, one vocabulary wins: started by the major search engines and extended through a public community process. [src]

  9. 6 Dec 2016
    measures writing
    Linked Open Vocabularies (LOV): A Gateway to Reusable Semantic Vocabularies on the Web

    A curated catalogue of reusable vocabularies, recording how they link to one another, their versions and maintainers, to help publishers choose existing vocabularies. [src]

Recent signals

Dated events that show the problem moving, newest last.

  1. 19 Mar 2026

    Schema.org 30.0 adds equivalence annotations that map its terms to GS1, Dublin Core and Open Graph. Schema.org[src]

Open now

Under each question, the answers people have put forward or built. The catalogue gives no odds on them.

  • How should publishers choose among hundreds of overlapping vocabularies? [src1][src2]
    LOV lists 920 vocabularies; its paper argues that data publishers struggle to decide which to use.
  • How good can automatic alignment between ontologies get? [src]
    The Ontology Alignment Evaluation Initiative has measured matching systems every year since 2004.
    • Maintainers publish the mappings by hand. Schema.org
      Schema.org 30.0 states its equivalences to GS1, Dublin Core and Open Graph terms itself.[src]

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