linked data and the implications for library cataloguing: metadata models and structures in the...

Linked data and the implications for library cataloguing:

metadata models and structures in the Semantic Web

Gordon DunsirePresented at the Canadian Library Association Annual Conference, 26-29 May 2011, Halifax,

Nova Scotia

Outline

Context: evolution of the catalogue recordRDF 101Library metadata models/schemas in RDF

FRBR, RDA, ISBD, DCT, BiBO, ...From record to triples: worked example

A short historyof 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

MetadataDonated 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 wordExpression

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 discCarrier type:Term:

RDA content type

Term:

RDA carrier type

Donor:

Title:

Amazon/Publisher

Where is the record?Implicit, not explicit

Everywhere and nowhereA semantic Web will allow machines to create the

record just-in-timeWe will not have to maintain records just-in-case

The user will have control over the presentationI want to see an archive or library or museum or Amazon

or Google or Flickr or ? displayAnd 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 MuseumSpoken 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” statementsA 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 bookNature of the statement = Predicate: has titleValue 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-processingHuman labels (“This book”, “has title”) no good

Same thing, different labels; different things, same label

Exploit the utility of the URLMachine-readable, regular syntax, unambiguous

Uniform Resource Identifier (URI)

Uniform Resource IdentifierCan be any unique combination of numbers and

lettersNo intrinsic meaning; it’s just an identifying label

Can look like a URLhttp://iflastandards.info/ns/isbd/elements/P1001But does not lead to a Web page (in principle ...)

RDF requires the subject and predicate of triple to be URIsObject can be a URI, or a literal string (“Treasure island”)

Namespaces

URI can be constructed from a base plus a unique, identifying suffixhttp://iflastandards.info/ns/isbd/elements/+ P1001

Base is known as a namespaceCan be abbreviated by human programmer

“isbd” = http://iflastandards.info/ns/isbd/elements/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-processableMetadata 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 RegistryCan assign a running “number” to the base to

create a new URISet of properties for creating basic triples

Properties = predicatesrdfs:label for assigning a human-readable label to

the subjectisbd:P1001 - rdfs:label - “has content form”

Subject Predicate Object

isbd:P1001 rdfs:label “has content form”

Subject Predicate Object

isbdcf:T1008 skos: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 + dateContent rules?

Mandatory Not repeatable Aggregation of simpler elements

Syntax of aggregation (punctuation)

Getting triples from records

Linking Open Data cloud (LOD)

Diagram by Richard Cyganiak and Anja Jentzsch. http://lod-cloud.net/

LOD: “Library” corner

Why get involved?

To share our dataWe work for “society”

To share our expertise and experience150 + 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 metadataIn comparison with other communities

Each record may generate many triples200 “raw” triples (no inferences) per MARC record?

Very, very large numbers of triplesBillions? Trillions?

1. Take a recordField/attribute ValueRecord ID 54321Title Museum archives: an introductionAuthor Wythe, DeborahDate 2004LCSH Museum archivesMedia/GMD ElectronicContent form Text

2. Disaggregate to single statementsRecord Attribute Value54321 (has) title Museum archives: an

introduction54321 (has) author Wythe, Deborah54321 (has) date 200454321 (has) LCSH Museum archives54321 (has) media type Electronic54321 (has) content form Text

3. Create URI for record

Must be unique, so 54321 no good on its ownhttp URIs are a good thing (W3C)So add record ID to a unique http domain

E.g. http://MyLibraryX.com (unique to the library)+ 54321

http://MyLibraryX.com/54321(or http://MyLibraryX.com#54321)

This is not a URL!

4. Replace record ID with URIURI Attribute Valuemlx:54321 (has) title Museum archives:

an introductionmlx:54321 (has) author Wythe, Deborahmlx:54321 (has) date 2004mlx:54321 (has) LCSH Museum archivesmlx:54321 (has) media type Electronicmlx:54321 (has) content form Text

“mlx” = qname (xmlns) = shorthand for “http://MyLibraryX.com/”

5. Find URIs for attributesAttributes are modelled as RDF properties (predicates) in

“element set” namespacesE.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 attributeNearest property minimises loss of information

Get URI for property If no suitable property, choose another namespace

Properties do not have to come from single namespaceMatch and mix!

5 (cont). Find URI for titlehttp://purl.org/dc/terms/title (dct:title)http://iflastandards.info/ns/isbd/elements/

P1014 (isbd:P1014)hasTitleProper

http://RDVocab.info/Elements/titleProper (rdaGR1:titleProper)

5 (cont). Find URI for authordct:creatorrdarole:author(isbd does not cover “headings”)

5 (cont). Find URI for datedct:dateisbd:P1018

hasDateOfPublicationProductionDistributionrdaGr1:dateOfPublication

5 (cont). Find URI for LCSHLCSH is a subject vocabulary

Controlled termsSo attribute is really “subject”

And the term itself is the valuedct:subject

5 (cont). Find URI for media typeAssuming record uses new ISBD Area 0 ...isbd:P1003

hasMediaType

5 (cont). Find URI for content formAssuming record uses new ISBD Area 0 ...isbd: P1001

hasContentForm

6. Replace attributes with URIsURI URI Valuemlx:54321 isbd:P1014 Museum archives:

an introductionmlx:54321 rdarole:author Wythe, Deborahmlx:54321 isbd:P1018 2004mlx:54321 dct:subject Museum archivesmlx:54321 isbd:P1003 Electronicmlx:54321 isbd:P1001 Text

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 URILinked data!

Values from controlled vocabularies may have URIsPossible vocabularies: author, subject, ISBD Area 0NOT: title, date

For author: Virtual International Authority File (VIAF)For LCSH: Library of Congress Authorities &

VocabulariesFor ISBD Area 0: Open Metadata Registry

7 (cont). Find URI for authorAuthor: Wythe, DeborahVIAF: http://www.viaf.org/

viaf:31899419/#Wythe,+Deborah

7 (cont). Find URI for subject (LCSH)LCSH: Museum archivesLoC: http://id.loc.gov/authorities/

lcsh:/sh85088707#concept

7 (cont). Find URIs for ISBD Area 0

Media type: ElectronicISBD media type

isbdmt:T1002Content form: TextISBD Content form

isbdcf:T1009

8. Replace values with URIssubject predicate objectmlx:54321 isbd:P1014 “Museum archives: an

introduction”mlx:54321 rdarole:author viaf:31899419/#Wythe,

+Deborahmlx:54321 isbd:P1018 “2004”mlx:54321 dct:subject lcsh:/

sh85088707#concept mlx:54321 isbd:P1003 isbdmt:T1002mlx:54321 isbd:P1001 isbdcf:T1009

9. Publish triples (linked data)mlx:54321 | isbd:P1014 | “Museum archives: an

introduction” mlx:54321 | rdarole:author | viaf:31899419/#Wythe,

+Deborahmlx:54321 | isbd:P1018 | “2004”

mlx:54321 | dct:subject | lcsh:/sh85088707#concept

mlx:54321 | isbd:P1003 | isbdmt:T1002

mlx:54321 | isbd:P1001 | isbdcf:T1009

Linked data chainsmlx:54321 | dct:subject | lcsh:/sh85088707#concept

lcsh:/sh85088707#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:31899419/#Wythe,

+Deborahmlx:54321 | isbd:P1018 | “2004”

mlx:54321 | dct:subject | lcsh:/sh85088707#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 Record To Statement(s) = triple(s)

But metadata display ...... aggregates triples (from multiple sources) to create records on the fly

Thank you

gordon@gordondunsire.comOpen Metadata Registry

http://metadataregistry.org/