RDF and ontology mappings: Difference between revisions

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Revision as of 18:41, 26 July 2026

Every NeoWiki page's Subjects are available as RDF. The same data is offered in two ways:

A native projection in NeoWiki's own vocabulary. Lossless, always available, no setup.
Ontology projections that re-express the data in an established vocabulary such as the Europeana Data Model (EDM). Each one is defined by a Mapping page.

Each export is produced on demand from the page's current data and downloads as a Turtle or TriG file. A projection can also be kept in a SPARQL store and queried live. This wiki has such a store: see SPARQL queries.

The Mapping page

Each Mapping page targets one ontology, named by the page title, and holds an entry for every mapped Schema. Special:Mappings lists them all; this wiki ships one:

Mapping:EDM: the Person, City, Artwork and Artist Schemas, all mapped to EDM

Explore the projections

Follow these in order; each link downloads the projection so you can read it.

You don't need these links to reach an export: on any subject page, the Data tab offers per-projection downloads (Turtle or TriG) and a copy-IRI control, and the sidebar has a View RDF link.

Pablo Picasso, native vs EDM: the native file has everything, including the two-layer "Born in" relation and the page metadata; the EDM file is an edm:Agent carrying only the mapped vocabulary, with the unmapped Source absent.
Málaga, EDM: an edm:Place with the very same entity IRI that Picasso's rdaGr2:placeOfBirth points at, because sibling projections share entity IRIs.
The Milkmaid, EDM: an edm:ProvidedCHO whose dc:creator is the IRI of Vermeer (an edm:Agent) and whose edm:currentLocation is the Rijksmuseum.
Johann Sebastian Bach, EDM: Bach's birth is modelled as its own Birth Subject instead of flat fields, so his edm:Agent projects sparse. Same Person Schema as Picasso, a different modelling style.
ACME Inc, EDM: its Company Schema has no EDM Mapping, so the EDM projection comes back empty. An unmapped Schema is simply left out, so the projection stays conformant.

Learn more

Special:Mappings: every ontology Mapping on this wiki
RDF export reference
Ontology mapping reference
Person-to-EDM worked example
Tell us what you need from RDF and ontology mapping: join the discussion.

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 * '''Ontology projections''' that re-express the data in an established vocabulary such as the [https://pro.europeana.eu/page/edm-documentation Europeana Data Model] (EDM). Each one is defined by a '''Mapping''' page.
-Each export is produced on demand from the page's current data and downloads as a Turtle or TriG file. A projection can also be kept in a SPARQL store and queried live. See [[SPARQL queries]] on wikis that have a store configured, such as the NeoWiki development stack.
+Each export is produced on demand from the page's current data and downloads as a Turtle or TriG file. A projection can also be kept in a SPARQL store and queried live. {{#ifexist:SPARQL queries|This wiki has such a store: see [[SPARQL queries]].}} {{#ifexist:EDM queries|The store holds the native and the EDM projection side by side, so a query can join across both — see [[EDM queries]].}}
 == The Mapping page ==