◆ Semantic Web Catalogue

Design issue

Vocabulary

What terms do we share?

tension
Formal against folk: expert-built schemes and ontologies against tags anyone can add (ontology against folksonomy); one shared vocabulary against many local ones.
also
Knowledge organization, Classification, Terms
scheme
design issues

Threads (4)

Long-running problems under this issue, told step by step. All threads.

  • From catalogue card to web data 1876–2024 open 11 steps

    Can library catalogue records, built for card drawers and MARC, become first-class data on the Web?

  • One vocabulary or many 1984–2016 open 9 steps

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

  • Ontology against folksonomy 1876–2018 open 11 steps

    Should shared terms be designed by experts in advance, or emerge from the words people actually use?

  • Hand-built meaning or learned meaning 1959–2024 open 11 steps

    Do machines get meaning from knowledge people write down, or from patterns in large amounts of data?

Who answered it

This issue's row of the map: which traditions' works mainly answer it, and the earliest from each.

traditionworksearliest
Hypertext
Knowledge representation 16 WordNet 1985
Databases 2 YAGO 2007
Machine learning 1 WordNet 1985
Web standards 24 Dublin Core 1995
Search 3 Schema.org 2011
Social web 10 FOAF 2000
Open knowledge 1 Archive of Our Own 2009
Decentralized web 2 Activity Streams 2.0 2017
Libraries, archives and museums 18 Dewey Decimal Classification 1876
Life sciences 5 Protégé 1987
Media 8 TV Tropes 2004
Geospatial 3 Basic Geo (WGS84 lat/long) Vocabulary 2003
Commerce and supply chain 3 GoodRelations 2008
Government and law 3 EuroVoc 1984
Finance 2 XBRL 1998
Industry and engineering 4 SAREF 2015

16 of 17 traditions have taken up this question as a work's main issue; a work in several traditions counts in each. Same counts as the full map.

Timeline

Works on this question, its main or a secondary one, each shown once in date order; filter by tradition to follow one community. Bars run from start to end where both are known; marks people, projects and organizations still active. 14 entries have no date and are not shown. Hover over or focus an entry to draw its links. Scroll sideways, or use the decades above.

Lineage (69)

Works whose main question this is, by type, oldest first.

Concepts 11

  • Folksonomy 2004 concept technique

    Classification that emerges from many users freely tagging content; the term was coined by Thomas Vander Wal in 2004 and became the bottom-up counterpoint to formal ontologies.

  • Hashtag 2007 concept

    A word prefixed with '#' that groups posts by topic. Chris Messina proposed it on Twitter in August 2007; it became the most widely used folksonomy, a vocabulary made by its users rather than designed in advance.

  • Curated folksonomy 2018 concept technique

    Free tagging by users combined with volunteers who link synonymous tags to canonical ones, keeping the users' words while adding a controlled structure; named by Julia Bullard.

  • Controlled vocabulary concept technique

    Agreed list of terms for indexing and retrieval, so that one subject is always described the same way.

  • Faceted classification concept technique

    Classification that describes a subject by combining independent facets, such as topic, place and time, instead of placing it in one fixed hierarchy.

  • Metadata concept technique

    Data that describes other data or documents, such as author, date, subject or format.

  • Ontology (information science) concept formalism

    Formal description of the concepts in a domain and the relations between them, which software can use to reason about data.

  • Ontology spectrum concept

    Scale of increasingly formal knowledge organization, from catalogues and glossaries through thesauri and taxonomies to logic-based ontologies, drawn to clarify the many things called 'ontologies'.

  • Taxonomy concept technique

    Classification of things or concepts into a hierarchy of categories.

  • Thesaurus (information retrieval) concept technique

    Controlled vocabulary whose terms are linked by broader, narrower, related and preferred-term relations.

  • Upper ontology concept formalism

    Ontology of very general categories, such as object, process and quality, shared across domains. Examples include Cyc's upper ontology, BFO, DOLCE and SUMO.

Writings 14

Standards 29

  • Dewey Decimal Classification 1876 standard ★ seminal

    Library classification that sorts knowledge into ten main classes with decimal subdivisions, first published by Melvil Dewey in 1876.

  • Universal Decimal Classification 1905 standard

    Library classification adapted from Dewey's system by Otlet and La Fontaine to index all recorded knowledge; still maintained today.

  • Colon Classification 1933 standard ★ seminal

    S.R. Ranganathan's library classification, which builds subject numbers from facets joined by colons.

  • Dublin Core 1995 standard ★ seminal

    Small set of metadata elements, such as title, creator and date, for describing resources on the Web; it began at a 1995 workshop in Dublin, Ohio.

  • SHOE c. 1996 standard

    Simple HTML Ontology Extensions: an early language for writing ontologies and annotating web pages with machine-readable claims, developed at the University of Maryland around 1996; among the first ontology languages made for the Web.

  • XBRL 1998 standard

    Format for business and financial reports whose taxonomies define each reporting concept and its relations, begun by Charles Hoffman in 1998; regulators, securities commissions and tax agencies worldwide receive filings in it, and Inline XBRL embeds the tags in an ordinary HTML report.

  • FOAF 2000 standard ★ seminal

    RDF vocabulary for describing people, their online accounts and who they know; one of the first widely used Semantic Web vocabularies.

  • SNOMED CT 2002 standard

    Logic-based clinical terminology of medical concepts and their relations, released in January 2002 and maintained by SNOMED International.

  • XFN 2003 standard

    Microformat from 2003 for marking up how the person behind a link relates to you, such as friend, colleague or met, using the rel attribute; Google's Social Graph API crawled it.

  • Basic Geo (WGS84 lat/long) Vocabulary 2003 standard

    Small RDF vocabulary from January 2003 for points with latitude, longitude and altitude, made in the W3C Semantic Web Interest Group; never a W3C standard, it became the most used way to give a thing a position in RDF.

  • RDF Schema 2004 standard ★ seminal

    W3C vocabulary for describing classes and properties of RDF data; the first schema language for RDF.

  • Music Ontology 2007 standard

    RDF vocabulary for music, first released in 2007, describing artists, works, recordings and releases, and the performances and recordings that connect them as events in time. It reuses FRBR's split between a work and its expressions, and FOAF for people.

  • SIOC 2007 standard

    RDF vocabulary for describing posts, threads, forums and their authors, so that conversations on blogs, forums and mailing lists can be linked across sites; a W3C Member Submission of June 2007.

  • GoodRelations 2008 standard

    Martin Hepp's web vocabulary for products, prices and offers, adopted by Google, Yahoo, Bing and retailers such as Best Buy, and merged into schema.org in November 2012 as its commerce vocabulary.

  • SKOS 2009 standard ★ seminal

    W3C vocabulary for publishing thesauri, classification schemes and subject headings as Linked Data; a Recommendation since August 2009.

  • Open Graph protocol 2010 standard

    Facebook's 2010 vocabulary of meta tags that turn a web page into a rich object when shared; the first version was based on RDFa.

  • Schema.org 2011 standard ★ seminal

    Shared vocabulary for structured data in web pages, launched in 2011 by Bing, Google and Yahoo, with Yandex joining later that year.

  • BIBFRAME 2012 standard

    Library of Congress model for bibliographic data based on Linked Data, designed to replace the MARC formats; work began in 2012 and version 2.0 followed in 2016.

  • X Cards 2012 standard

    Twitter's meta tags, introduced in 2012, that control how a linked page is previewed in posts; like Open Graph, a platform vocabulary that most websites publish.

  • Financial Industry Business Ontology 2014 standard

    OWL ontology of financial contracts, instruments, parties and their relations, begun after the 2008 crisis as a shared vocabulary for analysis and regulatory reporting; developed by the EDM Council with the Object Management Group and in an open community process since 2020.

  • DCAT 2014 standard

    W3C vocabulary for describing datasets in data catalogues, used by government open-data portals; a Recommendation since January 2014.

  • SAREF 2015 standard

    Small OWL ontology for smart appliances and the Internet of Things, begun in 2014–15 in a study for the European Commission and continued by ETSI, with extensions for energy, buildings, agriculture and other sectors.

  • Activity Streams 2.0 2017 standard

    W3C vocabulary and JSON-LD format for describing social activities such as posts, likes and follows; a Recommendation since May 2017.

  • Semantic Sensor Network Ontology 2017 standard

    Joint W3C and OGC ontology, a Recommendation of 19 October 2017, for describing sensors, actuators, observations and samples, with the lightweight SOSA core for simple use; a 2023 edition has been in draft since September 2025.

  • Web of Things Thing Description 2020 standard

    W3C Recommendation of 9 April 2020 that describes a device's properties, actions and events in JSON that can be read as JSON-LD, so applications can work across Internet of Things platforms.

  • Common Information Model (electricity) standard

    The electricity industry's shared model of power networks, adopted by the IEC, so grid operators' software can exchange data about lines, equipment and measurements; its profiles are exchanged as RDF, including between Europe's transmission operators.

  • Europeana Data Model standard

    Europeana's RDF model for cultural heritage metadata. It reuses Dublin Core, SKOS and OAI-ORE so that each provider's own description is kept alongside Europeana's additions; it replaced the flat Europeana Semantic Elements.

  • GS1 Web Vocabulary standard

    GS1's terms for products, organisations and locations published as Linked Data and designed as an extension to schema.org.

  • Lexicon standard

    AT Protocol's schema language for records, API endpoints and event streams. Each schema is a JSON file named by a reverse-DNS identifier (NSID); it resembles JSON Schema and OpenAPI rather than RDF vocabularies.

Projects 15

  • Getty Vocabularies 1981 project

    Thesauri for art and cultural heritage: the Art & Architecture Thesaurus (from 1981), the Thesaurus of Geographic Names and the Union List of Artist Names. Published as linked open data from February 2014 under an open attribution licence.

  • EuroVoc 1984 project

    The EU's multilingual thesaurus of the subjects of its work, maintained by the Publications Office since 1984 in the 24 official languages and more.

  • WordNet 1985 project ★ seminal

    Lexical database of English begun in 1985 at Princeton's Cognitive Science Laboratory under George A. Miller: nouns, verbs and adjectives grouped into sets of synonyms linked by relations such as broader and part-of. It became a shared vocabulary for language processing and for knowledge bases such as YAGO.

  • Protégé 1987 project

    Free ontology editor from Stanford University, widely used to build OWL ontologies.

  • Gene Ontology 1998 project ★ seminal

    Ontology of gene and gene-product functions begun in 1998 by researchers working on fly, mouse and yeast genomes; one of the most used ontologies in biology.

  • UniProt 2002 project

    Database of protein sequences and functions run since 2002 by a consortium of the EBI, SIB and PIR; it publishes its data as RDF with a public SPARQL endpoint.

  • Delicious 2003 project

    Social bookmarking site founded by Joshua Schachter in 2003, where people saved links under their own tags; with Flickr it gave rise to the term folksonomy.

  • TV Tropes 2004 project

    Fan wiki, started in 2004, that names and catalogues the recurring devices of fiction and links them to the works that use them: a vocabulary of storytelling built entirely by its readers.

  • Semantic MediaWiki 2005 project

    Extension to MediaWiki that lets wiki pages carry typed, queryable data annotations.

  • OBO Foundry 2007 project

    Collective of biomedical ontology developers who share principles for building interoperable ontologies; it has led the OBO effort since 2007.

  • YAGO 2007 project

    Knowledge base built at the Max Planck Institute for Informatics that combines facts from Wikipedia with WordNet's taxonomy (later with schema.org's); with DBpedia, one of the first large knowledge bases extracted from Wikipedia.

  • Europeana 2008 project

    European Union portal to the digitised collections of thousands of cultural heritage institutions, launched in November 2008; it aggregates their metadata with the Europeana Data Model and publishes it as Linked Open Data.

  • New York Times linked open data 2009 project

    The New York Times's release of its subject headings as linked open data, beginning with about 5,000 people's names on 30 October 2009, mapped by hand to DBpedia and Freebase.

  • Archive of Our Own 2009 project

    Fan-fiction archive run by the Organization for Transformative Works, open since November 2009. Writers tag freely, and volunteer tag wranglers link the tags to canonical ones, a working middle way between taxonomy and folksonomy; it won a Hugo Award in 2019.

  • BBC dynamic semantic publishing 2010 project

    Approach the BBC used for its 2010 World Cup site: journalists' tags stored in an RDF triplestore against a football ontology and queried with SPARQL to build pages automatically.

Also bears on this (30)

Concepts 4

  • Entity–relationship model 1976 concept formalism

    Way of modelling a domain as entities, their attributes and the relationships between them, drawn as ER diagrams; introduced by Peter Chen in 1976 as a unified view of the network, relational and entity-set models.

  • Nanopublication 2010 concept technique

    Smallest unit of publishable scientific information: a single assertion written as RDF named graphs, bundled with its provenance and publication details so it can be cited and credited on its own.

  • Embedded structured data concept technique

    Machine-readable data inside ordinary HTML pages, written as microformats, RDFa, microdata or JSON-LD and usually using the schema.org vocabulary.

  • JSON web APIs concept technique

    Plain JSON over HTTP with each API defining its own fields, without shared vocabularies or global identifiers; the everyday alternative most developers chose over Linked Data.

Writings 5

Standards 14

  • MARC 1965 standard ★ seminal

    MAchine-Readable Cataloging: formats for library catalogue records, developed by Henriette Avram at the Library of Congress between 1965 and 1968 so that libraries could share records by computer; a US national standard by 1971 and international by 1973. MARC 21 (1999) is still the predominant format.

  • Text Encoding Initiative 1987 standard ★ seminal

    Guidelines for encoding texts for scholarly study, from a 1987 meeting of humanities and computing scholars at Vassar College; P3 appeared in 1994, P4 moved to XML in 2002 and P5 followed in 2007. It is the standard markup of the digital humanities.

  • UN/EDIFACT 1987 standard

    The UN's standard messages and syntax for electronic data interchange between businesses, such as orders and invoices, approved as ISO 9735 in 1987 after merging with the American proposals: machine-readable business documents a decade before the Web.

  • PICS 1996 standard ★ seminal

    Platform for Internet Content Selection: W3C labels describing the content of web pages, made to let parents filter what children see; the label specification became a Recommendation on 31 October 1996. The RDF specification calls it a predecessor of RDF.

  • FRBR 1998 standard ★ seminal

    Functional Requirements for Bibliographic Records: IFLA's conceptual model of the bibliographic universe as entities and relationships, separating the work from its expressions, manifestations and items; its final report was published in 1998.

  • CIDOC Conceptual Reference Model 1999 standard ★ seminal

    Ontology for museum and cultural heritage documentation from ICOM's documentation committee, first issued in 1999 and an ISO standard since 2006. It describes objects through the events in their history, such as production, acquisition and movement, so that records from different institutions can be integrated.

  • Topic Maps 2000 standard

    ISO standard for representing knowledge as topics, associations and occurrences; similar in expressive power to RDF and developed alongside it.

  • ISO 15926 2003 standard

    ISO standard for integrating the life-cycle data of process plants, including oil and gas facilities, with a generic data model (Part 2, 2003) and reference data libraries; Part 8 implements it in OWL and RDF.

  • FRBRoo 2006 standard

    Formal ontology joining the librarians' FRBR model with the museums' CIDOC CRM, begun in 2006, so that bibliographic and museum records share one model.

  • ccREL 2008 standard

    Creative Commons' RDF vocabulary for describing licences and attaching them to works, written into web pages with RDFa; submitted to the W3C in May 2008.

  • European Legislation Identifier 2012 standard

    Identifiers and an ontology for national and EU legislation, so each law and version has a stable web address and machine-readable metadata; the EU Council invited its adoption in October 2012.

  • Linked Art 2016 standard

    Community profile of the CIDOC CRM for describing artworks and other heritage objects, in JSON-LD and using the Getty Vocabularies, so that museum data is practical for developers; started in 2016.

  • ODRL 2018 standard

    Policy language for stating permissions, prohibitions and duties over content and data; the W3C's ODRL Information Model 2.2 became a Recommendation in February 2018.

  • Data Privacy Vocabulary 2022 standard

    Vocabulary for describing how personal and other data is processed, why and on what legal basis, made by a W3C community group from 2018; version 1 was published in December 2022. It is designed to support legal requirements such as the GDPR.

Projects 7

  • VIAF 1998 project

    Service that links the name authority files of national libraries and merges records for the same person or organization into one cluster. Begun in 1998 by the Library of Congress, the Deutsche Nationalbibliothek and OCLC; it now draws on more than 50 organizations in over 30 countries.

  • OpenStreetMap 2004 project ★ seminal

    Volunteer-made map of the world, started in 2004 because Britain's Ordnance Survey would not release its data under a free licence. Its features carry free-form key=value tags, a folksonomy steered by a wiki, and its data moved to the share-alike ODbL in 2012.

  • BBC Music and Programmes linked data 2007 project

    The BBC's pages for every programme (from 2007) and every artist (beta from July 2008), each a web page and an RDF description. Artists were keyed on MusicBrainz identifiers and linked to DBpedia, so a public broadcaster built on fan-made data.

  • Rich Snippets 2009 project ★ seminal

    Google search feature announced in May 2009 that shows ratings, prices and other details in results, read from microformats and RDFa in pages.

  • DBTropes 2009 project

    Linked data wrapper for TV Tropes, announced in December 2009, that turns the wiki's pages into RDF linking works of fiction to the tropes they use; by November 2010 about 6,000 of its 16,000 items were linked to DBpedia, and users could correct the extraction.

  • Web Data Commons 2012 project

    Project that extracts microdata, RDFa, JSON-LD and microformats data from the Common Crawl web corpus and publishes it for research.

  • Google Dataset Search 2018 project

    Search engine for datasets that indexes schema.org Dataset descriptions published on the Web.

People and organizations (81)

Linked to works on this question; the number counts those works.

Dan Brickley (6) · World Wide Web Consortium (6) · R.V. Guha (3) · Deborah McGuinness (2) · Denny Vrandečić (2) · Fabian M. Suchanek (2) · Frédérick Giasson (2) · Jim Hendler (2) · Markus Krötzsch (2) · Martin Hepp (2) · Natasha Noy (2) · OCLC (2) · Paul Otlet (2) · S.R. Ranganathan (2) · Alistair Miles · Armin Haller · BBC · Bernard Vatant · Charles Hoffman · Chris Messina · Christiane Fellbaum · Clay Shirky · Danh Le Phuoc · David Rager · Dean Allemang · EDM Council · ENTSO-E · Eric Meyer · Eric Miller · Evan Prodromou · Fadi Maali · George A. Miller · Gerhard Weikum · Getty Research Institute · Ghislain Auguste Atemezing · Gjergji Kasneci · Google · GS1 · Henri La Fontaine · James Snell · Jeff Heflin · Jérôme Euzenat · John Breslin · John Erickson · Joshua Schachter · Julia Bullard · Kerry Taylor · Krzysztof Janowicz · Lee Spector · Libby Miller · Library of Congress · María Poveda-Villalón · Mark Musen · Mark Sandler · Matt Mullenweg · Matthias Kovatsch · Max Völkel · Maxime Lefrançois · Melvil Dewey · Michael McCool · The New York Times · Open Geospatial Consortium · Organization for Transformative Works · Pavel Shvaiko · Pierre-Yves Vandenbussche · Robert J. Rovetto · Samer Abdallah · Sean Bechhofer · Sean Luke · Sebastian Kaebisch · Simon Cox · Stanford University · Steve Macbeth · Stuart Weibel · Takuki Kamiya · Tantek Çelik · Tom Gruber · Uldis Bojārs · Victor Charpenay · XBRL International · Yves Raimond