linked library data

Linked Library Data

Modeling Metadata for the [Semantic] Web

Presented 2010-11-19Columbia University Digital Library Seminar Series Corey A Harper

2010-11-19 Harper - Linked Library Data - Columbia University 2

Topical Overview

• Semantic Web Intro• Linked Open Data

– Graphs: Entity – Attribute – Value– A Few Examples

• Library Data


Topical Overview (cont)

• Linked Library Data– SKOS and Authority Control– FRBR and Bibliographic Data– National Libraries

• Resource Description and Access (RDA)

• Dublin Core Metadata Initiative


Semantic Web

• TBL’s original vision– “Weaving the Web” – 1999

• Then: Focus on Machine Reasoning – Scientific American Article

• Now: Focus on things & links– Reasoning becoming lower level


Semantic Web

• Originally:– Metadata standard built on XML– Metadata about “Web” things

• Eventually:– Metadata about all things– Metadata about relationships

between things


Semantic Web Terminology

• Resource: Any thing• Class: Abstraction of a type of thing• Individual: An instance of a class• Property: An attribute of an individual• Ontology: A domain specific collection of

classes and properties• Statement/Triple:

– A Resource (subject) - Nodes– A Property (predicate) - Arcs– A Value (object) - Nodes


Semantic Web Terminology

• Graphs: Representations of statements about resources

• Nodes: The Subjects and Objects in a Graph• Arcs: The Predicates in a Graph• Literals:

“Objects” represented as strings (constant values) rather than things (URI References)

• Domains and Ranges: Constraints on Nodes• For Example…


RDF

• Resource Description Framework• Formally Begun in 1999• Ideas from 1995• Finalized in 2004• Frighteningly complex at times…

– “Directed Labeled Graphs”


SemWeb Value Proposition

• Formally Modeled (Meta) Data• Formal Semantics Declaration• Increased Granularity compared to

record-based Metadata• Improved Interoperability


“The vast bulk of data to be on the Semantic Web is already sitting in databases … all that is needed [is] to write an adapter to convert a particular format into RDF and all the content in that format is available.”

-Tim Berners-Lee in an interview with the Consortium Standards Bulletin


Linked Open Data

• Use URIs as names for things • Use HTTP URIs so that people can look

up those names. • When someone looks up a URI, provide

useful information. • Include links to other URIs. so that they

can discover more things. http://www.w3.org/DesignIssues/LinkedData.html


http://www4.wiwiss.fu-berlin.de/bizer/pub/lod-datasets_2009-07-14.html


http://richard.cyganiak.de/2007/10/lod/lod-datasets_2010-09-22_colored.html


Linked Data Cloud

• Automated generation– Comprehensive Knowledge Archive N

etwork (CKAN)– Vocabulary of Interlinked Datasets (

voiD)– Basically, catalog your metadata!

• Recent criticism: data quality

http://www.ckan.net/about

http://www.ckan.net/about

http://semanticweb.org/wiki/VoiD




Data in the Cloud• Hubs in the May 2008 Version:

– FOAF– DBPedia

• Myriad Sources coming online:– Thompson Reuters– New York Times– British Broadcasting Corporation– Google and Facebook– More and More Library Data

–Geonames–MusicBrains


DBpedia

• Structured Wikipedia Data• Genres, Influences, External Links• Multi-lingual / Multi-script labels• Rich Semantics• Many linkages to other datasets

http://wiki.dbpedia.org/Interlinking


DBpedia

• 3.4 Million “things” described• Ontology based on “infoboxes”

– 1.5 million things classified

• Approx. 50,000 “Properties”– Approx. 1,200 defined in ontology

• Brief Example

http://wiki.dbpedia.org/Ontology

http://en.wikipedia.org/wiki/Bob_Dylan


Domain Modeling

• Starting from application / goal / function

“To guide and evaluate our designs, we need objective criteria that are founded on the purpose of the resulting artifact, rather than based on a priori notions of naturalness or Truth.” – Gruber, 1993

• Does this apply to Libraries? FRBRer?


DBPedia Model

• Partial basis in data entry conventions• InfoBox’s, and InfoBox Templates• Metadata Entry Format• Partial source of Ontology

– Class Structure– Vocabulary Design


DBpedia

• 3.4 Million “things” described• Ontology based on “infoboxes”

– 1.5 million things classified– http://wiki.dbpedia.org/Ontology

• Approx. 50,000 “Properties”– Approx. 1,200 defined in ontology


More Examples

• British Broadcasting Corporation– Programmes, Music, Wildlife

• Google Refine• Data.gov and data.gov.uk• NY Times


What *things* are in our data???


…Librarydata is extremelycomplicated


Bibliographic Data

• Rich stores of MARC, MODS, &c.• Robust Controlled Vocabularies

– Subject Heading lists– Code lists– Thesauri

• Emerging data model in FR*


Bibliographic Vocabs

• Bibliographic Ontology– Zotero, Omeka, EPrints and Others

• FRBR – unofficial– And now Official (Thank you IFLA!)

• ISBD


Library Authority Data

“Include links to other URIs. so that they can discover more things.”

Short of providing and linking to URIs, this *is* authority data.

This is what our authority files are for.


Library Controlled Vocabularies: Benefits

• Reputation - Trusted Tradition• Mature - Time tested and carefully

developed• General & Comprehensive - Cover

large knowledge spaces


SKOS

• Simple Knowledge Organization System

• Properties and Classes for describing Controlled Vocabulary

RDF Pageskos:primaryTopic

skos:person


LCSH in Dublin Core

• Encoding Scheme for DC Subject• No easy way to draw on equivelent

terms and cross-references• Abstract Model, RDF and SKOS

could enable applications to make use of the whole vocabulary


LCSH as a Web Service!

• Uses principles of linked data• lcsh.info -> id.loc.gov• People noticed when taken down• Links to French Subject Headings• URIs for Literal String lookup• http://id.loc.gov/authorities/label/World Wide Web

http://id.loc.gov/authorities/label/World%20Wide%20Web




Other Vocabularies

• Thesaurus for Economics• French Subject Headings• Swedish Subject Headings• IconClass (not on web yet)• OCLC Terminology Services• Dewey Decimal Classification• Virtual International Authority File


Linked Library Data

• VIAF, LCSH, MARC Codes• Open Library, XC, Kualli OLE• Library of Congress, OCLC• Hungarian, German, British, Swedish

National Libraries• Formalized Efforts: W3C, IFLA & RDA


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National Széchényi Library

“Our RDFDC, FAOF and SKOS statements are linked together. Our name authority is matched with the DBPedia name files and URI aliases are handled as owl:sameAs statements.” -Adam Horvath


W3C LLD XG

• “Incubator Group”• Membership:

– Researchers, Consultants, Librarians– National Libraries: Germany, France,

LoC, Sweden– OCLC & IFLA


W3C LLD XG Goals

• Collecting, Curating and Clustering over 50 Use Cases

• Mining use cases for functional requirements and design patterns

• Recommendations to W3C– Should lead to Working Groups


RDA Development

• RDA elements, roles and vocabularies have been provisionally registered

• IFLA FRBRer and ISBD elements and vocabularies have been officially registered

• Discussions about long term maintenance of both RDA and the vocabularies

• Effort to create multi-language RDA Vocabularies

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RDA Elements Listing

334!


RDA Elements Listing

334!

Base material


Detail: Base Material


Detail: Base Material

URI


RDA Base Material Vocabulary


RDA WEMI Relationships


Detail: RDA WEMI Relationship


Metadata Registries

• Formerly NSDL Registry– Now “Open Metadata Registry”– Managing Vocabularies– Providing Vocabulary Services

• DCMI Registry Community• DCMI Architecture Forum


DCMI and the Semantic Web

• Collaboration from the start• Libraries (esp. OCLC) were at the

table• Perception of DCMI as DCMES

– DCMI = Metedata Vocab / Framework– DCMES = Metadata Record Format


DCMI and the Semantic Web

• Every example above had dcterms• DCMI as Research Institute and

Metadata Think Tank– Modeling Work– Metadata Registries– Application Profiles– Description Set Profiles– Singapore Framework


Changing Role of DCMI

• Mike Bergman at DC2010:– Reference Metadata– Reference Concepts– Mapping Predicates

• “Mappings should be approximate”

– Usage Guidelines• Compliment to W3C Standards


Why Does This Matter?Our descriptions no longer stand alone!Connect our data with the rest of the WEBAllow others to reuse more easily

– FOAF– DBPedia– Geonames– MusicBrains– New York Times– Thompson Reuters– Government Data - data.gov– British Broadcasting Corporation


Conclusions

• Distributed bibliographic control environment– Linking Data– Focus on identification over description

• “In short, by treating values as non-literal resources and assigning URIs to them we give ourselves (and others) the hooks on which to hang further descriptions.” - Andy Powell


Endless possibilities

• This barely scratches the surface• The Giant Global Graph!!• With more soundly modeled

bibliographic and authority data…– Terminology Services– Context sensitive

interfaces– Customized Exhibits

– Mashups– Web Services– User Profiling– Collaboration tools


Continuing Challenges

• Emerging Technology• Design Patterns• Complexity (http-range14)• Existing Technical Infrastructure• Bootstrapping• Business Cases


More Information

• W3C LLD XG:http://www.w3.org/2005/Incubator/lld/wiki/Main_Page

• ALA LLD Interest Group:– http://kcoyle.net/lld-ala.html

• IFLA Semantic Web SIG– https://wiki.d-nb.de/x/vA10Ag

http://kcoyle.net/lld-ala.html

http://www.google.com/url?sa=D&q=https://wiki.d-nb.de/x/vA10Ag&usg=AFQjCNE0oW9GXN2mFhvplRz0PGKgRE8-iw


Thanks!

[email protected]

Questions?

linked library data

Documents

web thingseventually

metadata standard

things linksreasoning

http uris

things uri referencesdomains

particular format

entity attribute valuea

authority controlfrbr