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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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)

8. 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

9. Questions and comments?