Linked data and the implications for library cataloguing: metadata models and structures in the Semantic Web Gordon Dunsire Presented at the Canadian Library Association Annual Conference, May 2011, Halifax, Nova Scotia

Outline  Context: evolution of the catalogue record  RDF 101  Library metadata models/schemas in RDF  FRBR, RDA, ISBD, DCT, BiBO,...  From record to triples: worked example

A short history of the evolution of the library catalogue record

Lee, T. B. Cataloguing has a future. - Audio disc (Spoken word). - Donated by the author. 1. Metadata In the beginning the catalogue card

Author: Title: Content type: Provenance: Subject: Lee, T. B. Cataloguing has a future Spoken word Audio disc Metadata Donated by the author Carrier type: From flat-file record to relational record Name: Biography:... Name authority Term: Definition:... Subject authority Bibliographic description

Author: Title: Content type: Provenance: Subject: Lee, T. B. Cataloguing has a future Spoken word Audio disc Metadata Donated by the author Carrier type: From flat-file description to FRBR record Name: Biography:... Name authority Term: Definition:... Subject authority Bibliographic description Item Manifestation Author: Content type: Subject: Spoken word Expression Work

Lee, T. B. Metadata From FRBR record to extinction! Name: Name authority Term: Subject authority Item Manifestation Expression Work Provenance: Donated by the author Subject: Author: Title: Cataloguing has a future Content type: Spoken word Audio disc Carrier type: Term: RDA content type Term: RDA carrier type Donor: Title: Amazon/Publisher

Where is the record?  Implicit, not explicit  Everywhere and nowhere  A semantic Web will allow machines to create the record just-in-time  We will not have to maintain records just-in-case  The user will have control over the presentation  I want to see an archive or library or museum or Amazon or Google or Flickr or ? display  And by avoiding duplication, we can all get on with describing new stuff...

The hyperdimensional (Tardis) card Lee, T. B. Cataloguing has a future. - Audio disc (Spoken word). - Donated by the author. 1. Metadata Audio shop Lee Museum Spoken word archive W3C Library “TARDIS four port USB hub, for office-bound Time Lords: Open a time vortex on your desk” – Pocket-lint

RDF 101

Semantic Web  “machine-readable metadata”  Faster! 24/7/365! Global!  Metadata expressed as “atomic” statements  A simple, single, irreducible statement  The title of this book is “Treasure island”  In a standard machine-processable format  Resource Description Framework (RDF)

Resource Description Framework  Metadata statement constructed in 3 parts  “Triple”  The title of this book is “Treasure island”  Subject of the statement = Subject: This book  Nature of the statement = Predicate: has title  Value of the statement = Object: “Treasure island”  This book – has title – “Treasure island”  subject – predicate - object

Identifiers  Need unambiguous way of identifying each part of the triple for efficient machine- processing  Human labels (“This book”, “has title”) no good  Same thing, different labels; different things, same label  Exploit the utility of the URL  Machine-readable, regular syntax, unambiguous  Uniform Resource Identifier (URI)

Uniform Resource Identifier  Can be any unique combination of numbers and letters  No intrinsic meaning; it’s just an identifying label  Can look like a URL   But does not lead to a Web page (in principle...)  RDF requires the subject and predicate of triple to be URIs  Object can be a URI, or a literal string (“Treasure island”)

Namespaces  URI can be constructed from a base plus a unique, identifying suffix   + P1001  Base is known as a namespace  Can be abbreviated by human programmer  “isbd” =  isbd:P1001  Machine expands abbreviation for processing

Everything as triples in RDF  Every aspect of the metadata must be expressed in RDF to be machine-processable  Metadata about real-world objects (books, people, etc.)  Metadata about the predicates (definition, label, scope, etc.)  Common predicates apply to many types of thing (human-readable label, etc.)  High-level RDF namespaces (rdfs, owl)  RDF is expressed in RDF (“bootstrap”)

Library namespaces

Creating namespaces and URIs  FRBR/FRAD/FRSAD, ISBD, and RDA are using the Open Metadata Registry  Can assign a running “number” to the base to create a new URI  Set of properties for creating basic triples  Properties = predicates  rdfs:label for assigning a human-readable label to the subject  isbd:P rdfs:label - “has content form”

SubjectPredicateObject isbd:P1001rdfs:label“has content form”

SubjectPredicateObject isbdcf:T1008skos:prefLabel“spoken word”

Application profile  Need a way to specify how a useful “record” can be constructed from RDF triples  Which triples are involved, and from which namespaces?  Sequence? Repeatable? Mandatory?  Sub-component aggregations  Publication statement = place + name + date  Content rules?

MandatoryNot repeatableAggregation of simpler elements Syntax of aggregation (punctuation)

Getting triples from records

Linking Open Data cloud (LOD) Diagram by Richard Cyganiak and Anja Jentzsch.

LOD: “Library” corner

Why get involved?  To share our data  We work for “society”  To share our expertise and experience  years  To promote the power of libraries (and archives and museums)  To survive

From record to triples (in 9 stages)  Very large numbers of records  Catalogue records, finding aids, etc.  300 million; 1 billion?  High quality metadata  In comparison with other communities  Each record may generate many triples  200 “raw” triples (no inferences) per MARC record?  Very, very large numbers of triples  Billions? Trillions?

1. Take a record Field/attributeValue Record ID54321 TitleMuseum archives: an introduction AuthorWythe, Deborah Date2004 LCSHMuseum archives Media/GMDElectronic Content formText

2. Disaggregate to single statements RecordAttributeValue 54321(has) titleMuseum archives: an introduction 54321(has) authorWythe, Deborah 54321(has) date (has) LCSHMuseum archives 54321(has) media typeElectronic 54321(has) content formText

3. Create URI for record  Must be unique, so no good on its own  http URIs are a good thing (W3C)  So add record ID to a unique http domain  E.g. (unique to the library)    (or  This is not a URL!

4. Replace record ID with URI URIAttributeValue mlx:54321(has) titleMuseum archives: an introduction mlx:54321(has) authorWythe, Deborah mlx:54321(has) date2004 mlx:54321(has) LCSHMuseum archives mlx:54321(has) media typeElectronic mlx:54321(has) content formText “mlx” = qname (xmlns) = shorthand for “

5. Find URIs for attributes  Attributes are modelled as RDF properties (predicates) in “element set” namespaces  E.g. Dublin Core terms (dct); ISBD (isbd); FRBR (frbrer); RDA (rdaxxx); Bibliographic Ontology (bibo); etc.  Choose a namespace, find property with same (or closest) “meaning” (e.g. definition) as attribute  Nearest property minimises loss of information  Get URI for property  If no suitable property, choose another namespace  Properties do not have to come from single namespace  Match and mix!

5 (cont). Find URI for title  (dct:title)  (isbd:P1014)  hasTitleProper  (rd aGR1:titleProper)

5 (cont). Find URI for author  dct:creator  rdarole:author  (isbd does not cover “headings”)

5 (cont). Find URI for date  dct:date  isbd:P1018  hasDateOfPublicationProductionDistribution  rdaGr1:dateOfPublication

5 (cont). Find URI for LCSH  LCSH is a subject vocabulary  Controlled terms  So attribute is really “subject”  And the term itself is the value  dct:subject

5 (cont). Find URI for media type  Assuming record uses new ISBD Area 0...  isbd:P1003  hasMediaType

5 (cont). Find URI for content form  Assuming record uses new ISBD Area 0...  isbd: P1001  hasContentForm

6. Replace attributes with URIs URI Value mlx:54321isbd:P1014Museum archives: an introduction mlx:54321rdarole:authorWythe, Deborah mlx:54321isbd:P mlx:54321dct:subjectMuseum archives mlx:54321isbd:P1003Electronic mlx:54321isbd:P1001Text

7. Find URIs for values  If object of a triple is a URI, it can link to the subject of another triple with the same URI  Linked data!  Values from controlled vocabularies may have URIs  Possible vocabularies: author, subject, ISBD Area 0  NOT: title, date  For author: Virtual International Authority File (VIAF)  For LCSH: Library of Congress Authorities & Vocabularies  For ISBD Area 0: Open Metadata Registry

7 (cont). Find URI for author  Author: Wythe, Deborah  VIAF:  viaf: /#Wythe,+Deborah

7 (cont). Find URI for subject (LCSH)  LCSH: Museum archives  LoC:  lcsh:/sh #concept

7 (cont). Find URIs for ISBD Area 0  Media type: Electronic  ISBD media type  isbdmt:T1002  Content form: Text  ISBD Content form  isbdcf:T1009

8. Replace values with URIs subjectpredicateobject mlx:54321isbd:P1014“Museum archives: an introduction” mlx:54321rdarole:authorviaf: /#Wythe,+ Deborah mlx:54321isbd:P1018“2004” mlx:54321dct:subjectlcsh:/sh #conce pt mlx:54321isbd:P1003isbdmt:T1002 mlx:54321isbd:P1001isbdcf:T1009

9. Publish triples (linked data) mlx:54321 | isbd:P1014 | “Museum archives: an introduction” mlx:54321 | rdarole:author | viaf: /#Wythe,+Deborah mlx:54321 | isbd:P1018 | “2004” mlx:54321 | dct:subject | lcsh:/sh #concept mlx:54321 | isbd:P1003 | isbdmt:T1002 mlx:54321 | isbd:P1001 | isbdcf:T1009

Linked data chains mlx:54321 | dct:subject | lcsh:/sh #concept lcsh:/sh #concept | skos:related | rameau:XXX rameau:XXX | frbrer:isSubjectOf | mly:98765 rameau:XXX | skos:prefLabel | “archives du musée” mly:98765 | rda:titleOfTheWork | “Managing archives in museums”

Linked data cluster = “record” mlx:54321 | isbd:P1014 | “Museum archives: an introduction” mlx:54321 | rdarole:author | viaf: /#Wythe,+Deborah mlx:54321 | isbd:P1018 | “2004” mlx:54321 | dct:subject | lcsh:/sh #concept mlx:54321 | isbd:P1003 | isbdmt:T1002 mlx:54321 | isbd:P1001 | isbdcf:T1009

Metadata focus Shift of focus of metadata creation, maintenance, storage, preservation (by professionals, amateurs, machines) From RecordTo Statement(s) = triple(s) But metadata display aggregates triples (from multiple sources) to create records on the fly

Thank you   Open Metadata Registry 