RDF and ontology mappings: Difference between revisions

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Revision as of 11:52, 20 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 — see SPARQL queries on wikis that have a store configured, such as the NeoWiki development stack.

The Mapping page

Each Mapping page targets one ontology, named by the page title, and holds an entry for every mapped Schema. 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.

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 — and 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 — the 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 — a Schema without a Mapping is simply absent, which is how conformant output stays conformant.

Learn more

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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 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.
-== The Mapping pages ==
+== The Mapping page ==
-Each Mapping binds one Schema to one target ontology. This wiki ships four, all targeting EDM:
+Each Mapping page targets one ontology, named by the page title, and holds an entry for every mapped Schema. This wiki ships one:
-* [[Mapping:PersonToEDM]] — the Person Schema
+* [[Mapping:EDM]] — the Person, City, Artwork and Artist Schemas, all mapped to EDM
-* [[Mapping:CityToEDM]] — the City Schema
-* [[Mapping:ArtworkToEDM]] — the Artwork Schema
-* [[Mapping:ArtistToEDM]] — the Artist Schema
 == Explore the projections ==
@@ Line 19: / Line 16: @@
 Follow these in order; each link downloads the projection so you can read it.
-# '''Pablo Picasso''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Pablo Picasso}}/rdf native] vs [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Pablo Picasso}}/rdf?projection=edm EDM]: the native file has everything, including the two-layer "Born in" relation and the page metadata; the EDM file is an <code>edm:Agent</code> carrying only the mapped vocabulary, with the unmapped <code>Source</code> absent.
+# '''Pablo Picasso''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Pablo Picasso}}/rdf native] vs [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Pablo Picasso}}/rdf?projection=EDM EDM]: the native file has everything, including the two-layer "Born in" relation and the page metadata; the EDM file is an <code>edm:Agent</code> carrying only the mapped vocabulary, with the unmapped <code>Source</code> absent.
-# '''Málaga''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Málaga}}/rdf?projection=edm EDM]: an <code>edm:Place</code> — and the very same entity IRI that Picasso's <code>rdaGr2:placeOfBirth</code> points at, because sibling projections share entity IRIs.
+# '''Málaga''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Málaga}}/rdf?projection=EDM EDM]: an <code>edm:Place</code> — and the very same entity IRI that Picasso's <code>rdaGr2:placeOfBirth</code> points at, because sibling projections share entity IRIs.
-# '''The Milkmaid''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:The Milkmaid}}/rdf?projection=edm EDM]: an <code>edm:ProvidedCHO</code> whose <code>dc:creator</code> is the IRI of [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johannes Vermeer}}/rdf?projection=edm Vermeer] (an <code>edm:Agent</code>) and whose <code>edm:currentLocation</code> is the Rijksmuseum.
+# '''The Milkmaid''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:The Milkmaid}}/rdf?projection=EDM EDM]: an <code>edm:ProvidedCHO</code> whose <code>dc:creator</code> is the IRI of [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johannes Vermeer}}/rdf?projection=EDM Vermeer] (an <code>edm:Agent</code>) and whose <code>edm:currentLocation</code> is the Rijksmuseum.
-# '''Johann Sebastian Bach''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johann Sebastian Bach}}/rdf?projection=edm EDM]: Bach's birth is modelled as its own Birth Subject instead of flat fields, so his <code>edm:Agent</code> projects sparse — the same Person Schema as Picasso, a different modelling style.
+# '''Johann Sebastian Bach''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:Johann Sebastian Bach}}/rdf?projection=EDM EDM]: Bach's birth is modelled as its own Birth Subject instead of flat fields, so his <code>edm:Agent</code> projects sparse — the same Person Schema as Picasso, a different modelling style.
-# '''ACME Inc''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:ACME Inc}}/rdf?projection=edm EDM]: its Company Schema has no EDM Mapping, so the EDM projection comes back empty — a Schema without a Mapping is simply absent, which is how conformant output stays conformant.
+# '''ACME Inc''', [{{SERVER}}{{SCRIPTPATH}}/rest.php/neowiki/v0/page/{{PAGEID:ACME Inc}}/rdf?projection=EDM EDM]: its Company Schema has no EDM Mapping, so the EDM projection comes back empty — a Schema without a Mapping is simply absent, which is how conformant output stays conformant.
 == Learn more ==