Forging a Path for Linked Open Data at DPLA

Gretchen Gueguen Data Services Coordinator

Digital Public Library of America

DPLA by the numbers

8,000,000+ records 23 hubs and counting 1300+ contributing institutions

…3 major metadata schemas, 1 product-specific formats, 5 institution-specific formats

DPLA by the numbers

DPLA’s Metadata Application Profile

•  Originally developed between 2012 and 2013

•  Based on the Europeana Data Model •  Currently in version 3.1 •  Undergoing update to version 4

MAP v3.1

MAP v4

Namespaces •  Content in RDF (cnt): http://www.w3.org/2011/content#

•  Dublin Core (dc): http://purl.org/dc/elements/1.1/

•  Dublin Core Terms (dcterms): http://purl.org/dc/terms/

•  DCMI Type Vocabulary (dcmitype): http://purl.org/dc/dcmitype/

•  Europeana Data Model (edm): http://www.europeana.eu/schemas/edm/

•  Geonames (gn): http://www.geonames.org/ontology#

•  Open Annotation (oa): http://www.w3.org/ns/oa#

•  OAI Object Reuse and Exchange (ore): http://www.openarchives.org/ore/terms/

•  Resource Description Framework (rdf): http://www.w3.org/1999/02/22-rdf-syntax-ns#

•  RDF Schema (rdfs): http://www.w3.org/2000/01/rdf-schema#

•  Simple Knowledge Organization System (skos): http://www.w3.org/2004/02/skos/core#

•  World Geodetic System (wgs84): http://www.w3.org/2003/01/geo/wgs84_pos#

Expansion of Classes

•  Place •  Agent •  Concept

Examples of Provided Subjects

<dc:subject>figures (representations); trees; vines</dc:subject> <dc:subject authority=“lcsh” valueURI=“http://id.loc.gov/authorities/subjects/sh85073038”> Korea--History--Japanese occupations, 1910-1945</dc:subject>

Examples in JSON-LD "subject":[ { ”providedLabel” : ”figures (representations)” }, ], "subject":[ { ”concept” : ” Korea-- History--Japanese occupations, 1910-1945” “scheme” : “http://id.loc.gov/authorities/subjects” “exactMatch” : “http://id.loc.gov/authorities/subjects/sh85073038” }, ],

Enriched data; close match

Original Label

Standardized Rights Metadata

•  Knight Foundation-funded project to develop standardized namespace for rights metadata and a list of URIs for standard declarations

API

•  Native rdf triplestore serialized into JSON-LD

•  Currently based on MAPv3.1 •  Public website uses JSON-LD api •  Also available through the API directly •  Entire datastore available for download •  Implementation of MAPv4 will occur in

stored data, but will be mapped to MAPv3.1 for use in the API for the near future

Future Steps

•  Source of LOD? •  Portal with LOD? •  Service for adding LOD to library

bibliographic records?