Knowledge graph IRIs¶

The IISG knowledge graph is rebuilt nightly from the OAI-PMH endpoint and other sources. Each OAI record becomes a resource with a predictable IRI, so you can join your harvested data to the graph without a lookup table.

From OAI identifier to IRI¶

Strip oai:socialhistoryservices.org: from the identifier, then:

OAI local part	IRI	Graph
`1292895` (library record)	`https://iisg.amsterdam/id/item/1292895`	`https://iisg.amsterdam/graph/biblio`
`10622/ARCH02487` (archive)	`https://iisg.amsterdam/id/collection/ARCH02487`	`https://iisg.amsterdam/graph/archive`, `…/graph/findingaid`
`iish.evergreen.authority:264172`	`https://iisg.amsterdam/authority/<type>/264172`	`https://iisg.amsterdam/graph/authority`

Characters that aren't allowed in an IRI path segment are percent-encoded.

Authority pointers¶

A value ending in (NL-AMISG)<id> in oai_dc, or a $0 subfield with (NL-AMISG)<id> in marcxml, points to an authority record. Its IRI depends on the kind of heading:

Type	IRI pattern	RDF type
Person	`https://iisg.amsterdam/authority/person/<id>`	`sdo:Person`
Organisation	`https://iisg.amsterdam/authority/organization/<id>`	`sdo:Organization`
Event	`https://iisg.amsterdam/authority/event/<id>`	`sdo:Event`
Place	`https://iisg.amsterdam/authority/place/<id>`	`sdo:Place`
Topic	`https://iisg.amsterdam/authority/topic/<id>`	`sdo:DefinedTerm`
Period	`https://iisg.amsterdam/authority/period/<id>`	`sdo:DefinedTerm`
Form / genre	`https://iisg.amsterdam/authority/form/<id>`	`sdo:DefinedTerm`
Uniform title	`https://iisg.amsterdam/authority/title/<id>`	`sdo:CreativeWorkSeries`

If you only have the number, ask the graph which type it is:

SELECT ?authority ?type WHERE {
  VALUES ?type { "person" "organization" "event" "place" "topic" "period" "form" "title" }
  BIND(IRI(CONCAT("https://iisg.amsterdam/authority/", ?type, "/264172")) AS ?authority)
  ?authority ?p ?o .
}
GROUP BY ?authority ?type

SPARQL endpoint¶

Test endpoint

The examples in this documentation use a test endpoint. IISG's official knowledge graph is iisg.amsterdam/kg. It uses the same IRIs, but some examples give fewer results there. See beta.

	Official	Used in this documentation (test)
SPARQL endpoint	`https://api.druid.datalegend.net/datasets/IISG/iisg-kg/services/iisg-kg/sparql`	`https://sparql.zijdeman.nl`
Query UI	https://iisg.amsterdam/kg	https://kg.zijdeman.nl
Viewer	–	https://kb.zijdeman.nl (experimental)

Both speak the standard SPARQL 1.1 protocol (GET or POST).

Main vocabularies: schema.org (sdo:), RiC-O for archives, MARC relators (http://id.loc.gov/vocabulary/relators/) for roles, and IISG's own https://iisg.amsterdam/vocab/ for properties without a standard equivalent.

Example: library records about the topic Women, with their creators:

PREFIX sdo: <https://schema.org/>
PREFIX iisgv: <https://iisg.amsterdam/vocab/>
PREFIX rel: <http://id.loc.gov/vocabulary/relators/>

SELECT ?item ?name ?creatorName WHERE {
  ?item iisgv:topic <https://iisg.amsterdam/authority/topic/264172> ;
        sdo:name ?name .
  OPTIONAL { ?item rel:cre/sdo:name ?creatorName }
}
LIMIT 50