A new RKDartists schema.org modelling

09-07-2024

The RKD is proud to present an updated version of the RKDartists schema.org serialisation with its own SPARQL endpoints. For more information on how to use the RKD schema.org Knowledge Graph, please refer to this data story.

Are you an existing user of the SPARQL or ElasticSearch endpoints of the RKDartists set hosted at NDE? Please switch to the RKD's new endpoint. The NDE-hosted set will be removed soon, as the Termennetwerk is also connected to the RKD endpoint now. Existing users of the RKDartists schema.org Linked Open Data should be advised that the structure of the data has changed slightly to improve interoperability. This data story will outline the changes.

Do you use the Termennetwerk's GraphQL or Reconciliation api? Then, no changes are needed. These services are not affected by the switch.

Background

The RKD has recently published all its data as Linked Open Data in the RKD Knowledge Graph. This experience prompted the RKD to review the patterns used in its old RKDartists schema.org serialisation, currently hosted by the NDE. The RKD now presents an updated version of the dataset with new patterns that are entirely in line with the schema.org ontology. This new version strives to improve interoperability of the data and facilitate understanding of the dataset for those new to RKDartists.

Important! schema.org namespace changed to https://

Please take notice of the fact that the schema.org namespace has changed in version 12.0 from http:// to https:// . The schema.org website now lists https:// as the canonical URL. The new RKDartists data reflects that change.

What has changed?

Two key changes have been made to the RKDartists schema.org serialisation:

• conforming all patterns to schema.org
• removing elements that do not fit easily into the schema.org properties

Conforming to schema.org

Key point in the new patterns is conformity with the schema.org ontology. In practice, this means that the http://data.rkd.nl/def# namespace properties have been replaced by the appropriate schema.org properties. Additionally, the structure of the data has become less nested.

Compare this old pattern for circumstances of birth:

@prefix rkdo: <http://data.rkd.nl/def#> .
@prefix schema: <http://schema.org/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

<https://data.rkd.nl/artists/32439> rkd:Birth [
	schema:actor <https://data.rkd.nl/artists/32439> ;
	schema:endDate “1853-03-30”
	schema:startDate “1853-03-30”
	schema:location <https://data.rkd.nl/thesaurus/2056> ;
	a rkd:Birth, rdf:Description ]
.

To the new pattern:

@prefix schema: <http://schema.org/> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .

<https://data.rkd.nl/artists/32439> schema:birthdate “1853-03-30” ;
	schema:birthPLace <https://data.rkd.nl/thesaurus/2056> .

RKD namespace properties that have been replaced by schema.org properties

rkdo:Birth

The rkdo:Birth property has been replaced by the various schema.org properties related to birth circumstances:

• birthDate - the object is a schema.org Date Type, which may also be a time interval
• birthPlace - a place or places from the RKD thesaurus. For ease of use, the labels of the places are included.
• description - the description combines all relevant remarks fields. The leading text of the birth remarks field is "Birthplace and date remark"

rkdo:Death

Similarly to rkdo:Birth, this property has been replaced by the relevant schema.org properties:

• deathDate - the object is a schema.org Date Type, which may also be a time interval
• deathPlace - a place or places from the RKD thesaurus. For ease of use, the labels of the places are included.
• description - the description combines all relevant remarks fields. The leading text of the birth remarks field is "Place and date of death remark"

rkdo:Period_of_Activity and rkdo:Place_of_activity

Not unexpectedly, schema.org has no properties to entirely correctly model an artist's 'period of activity'. Nor does it allow for easy pairing of a timespan with 'place of activity'. Therefore, the RKD uses the schema.org Role Type to further specify these properties.

The RKD properties have been replaced by the following schema.org properties:

• hasOccupation - active period
• workLocation - locations of activity

The locations of activity use numbered IRIs with the following pattern: https://data.rkd.nl/artists/100511/occupation/1. These IRIs can be used for ordering the different locations of activity in chronological order.

Schema.org dataset as an entrypoint to the RKD Knowledge graph

The second key change is the new relationship between the RKDartists schema.org data and the rich RKD Knowledge Graph. Now that the RKD has published all its data as Linked Open Data in the RKD Knowledge Graph, the schema.org representation is no longer the only data representation of RKDartists. Rather, the full dataset can be found in the RKD Knowledge Graph.

Therefore, the schema.org representation has, even more than before, the status of accessible entrypoint to the RKD data. It serves to make tombstone information about the artists and institutions quickly and easily available in a well-known format.

In practice, this has lead to the removal of several data elements that don't comfortably fit the schema.org model from the Artists in schema.org dataset. These elements are now accessible from the Knowledge Graph](https://rkd.triply.cc/rkd/RKD-Knowledge-Graph) through a federated query. For examples, see the RKDartists in schema.org data story.

List of removed elements:

• birthplace coordinates
• place of death coordinates
• see also (link to collaborative artists) + see also remark
• remarks on the period of activity
• education + remarks
• coordinates of places of activity
• remarks on places of activity
• teacher at academy/university + remark
• awards won + remarks
• group membership + remarks

Contact

For more information, please contact info@rkd.nl.