Recording RDA data as linked data Gordon Dunsire PCC URI Task Group, 11 April 2018

Kinds of recorded data RDA is designed to support a wide range of data carrier architectures for storage and display Flat-file: card and other print-based catalogues Local (Closed-world) Bib/Authority: MARC, etc. RDBMS: Table for each entity, row keys (IDs) Global (Open-world) RDF: Classes, properties, and IRIs RDA uses RDF to record data for RDA Reference (entities, elements, and vocabulary encoding schemes) Provides data for RDA Toolkit (Glossary, element reference, navigation) Available from RDA Registry under open license

RDA recording methods RDA provides instructions for four methods of recording data values: Unstructured description Transcription; free-form notes; uncontrolled human-readable appellation (name, title) Structured description Multiple values with string encoding scheme; value with syntax encoding scheme; controlled human-readable appellation (access point) Identifier Machine-readable appellation (local) IRI Machine-readable appellation (global) An appellation references an instance of an entity

Recording methods for related data "note on related entity 2" Keyword index "access point for related entity 2" Authority file RDA Entity 1 is related to Standard identifier system "identifier for related entity 2" This diagram shows all four recording methods in use to reference a related entity. The diagram can be interpreted as an RDF graph for linked data, or as a relational schema for a local database. RDA Entity 2 Semantic Web

Strings, things, and Nomens Entity (thing) has appellation has nomen string Nomen “nomen string" Status (VES) Timespan has date of usage has status of identification Name Authority file

Beyond RDA RDA is an implementation of the IFLA Library Reference Model RDA Entity LRM Res rdfs:subClassOf Domains and ranges of properties are specified as RDA entities RDA unconstrained properties do not specify domain or range Definition terms are given “in the vernacular”: no special meaning is intended for “resource” or “agent”. RDA unconstrained (not LRM) RDA property rdfs:subPropertyOf

Linking RDA data RDA uses RDF maps to link RDA entities, classes, and terms to external vocabularies Map = set of mappings between source and target elements Usually published in Terse Triple Language or N-triple serializations If there is no target representation in RDF, “map” is published as an alignment (data crosswalk, not linked data)

Data provenance Record the source of a transcribed data value recorded for an unstructured description Record the string/syntax encoding scheme used to derive the data value recorded for an access point Record the vocabulary encoding scheme used as a source of the data value recorded for an access point or identifier “Reify” the RDA data statement and relate it to the scheme or source as a Manifestation Data statement has source of information Manifestation

Questions and comments? rscchair@rdatoolkit.org http://www.gordondunsire.com/presentations.htm