SWEO Community Project: Linking Open Data on the Semantic Web

Common Vocabularies / Ontologies / Micromodels

This page collects links to vocabularies, ontologies and micromodels that are commonly used to publish RDF data on the Semantic Web.

In order to make it easier for client applications to do something useful with your data, it is recommended to use terms from these vocabularies wherever they fit. Feel free to mix terms from different vocabularies and to extend the vocabularies with additional terms in your own namespace. The background of this 'term cherry-picking' approach is for example explained in this Gov 2.0 Expo 2010 video by TimBL.

The page is part of the community project SweoIG/TaskForces/CommunityProjects/LinkingOpenData

Commonly used Vocabularies

Friend-of-a-Friend (FOAF) provides terms for describing people and their social network
SIOC Semantically-Interlinked Online Communities
DOAP Description of a Project
Dublin Core Defines general metadata attributes.
SKOS Simple Knowledge Organization System
SKOS DataZone list of vocabularies available in SKOS schema
Review Vocabulary provides terms for representing reviews.
GoodRelations provides terms for describing products and business entities.
Music Ontology provides terms for describing artists, albums, tracks, but also performances, arrangements, etc.
Organization Ontology for describing the structure of organizations.
Linking Open Description of Events (LODE) provides terms for describing the basic properties of an event and contains a list of axioms expressing mapping relationships with other ontologies such as DOLCE, CYC, CIDOC-CRM, Event Ontology, F, and SEM.
Google, Yahoo and Microsoft have agreed on vocabularies for publishing strucutred data on the Web. Their shared 'ontology' is maintained on schema.org.
MarineTLO (core) Ontology is a top-level ontology for the marine domain (also applicable to the terrestrial domain) and MarineTLO (imarine) Ontology is an extension and operational version of the MarineTLO core.

The State of the LOD Cloud document provides statistics about commonly used vocabularies (October 2010)

Blog post listing the 100 most common RDF namespaces (August 2006)

The paper Ding, Finin: Characterizing the Semantic Web on the Web gives an overview about which vocabularies were used in May 2006.

Vocabulary Listings

There are several sites collecting RDF vocabularies and OWL ontologies. Try to reuse these before inventing something new.

Vocabulary Mappings

Some vocabularies provide different URIs to describe equivalent (or more / less precise) resources. It seems important to define mappings (vocabulary links) between them.

Vocabulary Mapping Discovery

The Web of Data contains large amounts of instance data with instances being partly interlinked between data sources. The instance data as well as the connections can be used to mine vocabulary mappings (vocabulary links) from the Web of Data. Existing work is this space is:

BLOOMS - Ontology Alignment for Linked Data
Capturing Emerging Relations between Schema Ontologies on the Web of Data
The R2R Framework provides for publishing expressive mapping on the Web and for interlinking Mappings with Vocabulary Terms and Dataset Descriptions.

Micromodels / Microformats

Microformats define schemata for embedding data into HTML pages. Data that is published using a microformat can be transformed to RDF using GRDDL. See Microformat FAQs for RDF Fans

Linking Properties

This section collects poposals on which properties to use to set links between different entities.

ESW Wiki: PropertiesForLinking
Alexandre Passant: FOAF geonames and more plus answers by different people.
owl:sameAs as the standard way of saying that two data items in different data sources are about the same resource.
Bernard Vatant: Ideas for a Linking Vocabulary