What is Linked Data, and What Does It Mean for Libraries?

What is Linked Data,

and What Does It Mean for Libraries?

Emily Dust NimsakontNLA/NEMA Conference

October 15, 2010

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What is Linked Data,

and What Does It Mean for Libraries?

Emily Dust NimsakontNLA/NEMA Conference

October 15, 2010

Could

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This is an overview…

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What is Linked Data?

Wikipedia says…

“The term Linked Data is used to describe a method of exposing, sharing, and connecting data via dereferenceable URIs on the Web.”

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

Linked Datavs.

Semantic Webvs.

Web 3.0

“I have a dream for the Web [in which computers] become capable of analyzing all

the data on the Web – the content, links, and transactions between people and computers.”

Tim Berners-Lee, 1999

hypertextvs.

hyperdata

web of documentsvs.

web of data

Currently the Web is a system of

interconnected documents.

People use hyperlinks to navigate from one

document to another.

resource

resource

resource

resource

resource links to

links to

links to

links to

documentsvs.

things

HTML

<h1>This is a heading.</h1>

<p>This is a paragraph.</p>

RDF/XML

<rdf:Descriptionrdf:about="http://www.recshop.fake/cd/Empire Burlesque"> <cd:artist>Bob Dylan</cd:artist> <cd:country>USA</cd:country> <cd:company>Columbia</cd:company> <cd:price>10.90</cd:price> <cd:year>1985</cd:year></rdf:Description>

http://www.w3schools.com/rdf/rdf_example.asp

Relationships are key

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People can understand relationships between things.

But machines should be able to understand these relationships too.

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We are used to connecting pieces of information based on their context.

Title: A Christmas CarolAuthor: Charles Dickens

Linked Data makes the relationships explicit.

Charles Dickens is the author of A Christmas Carol.

Linked Data makes the Web into a database.

Linked Data principles

Tim Berners-Lee, “Linked Data-Design Issues.” http://www.w3.org/DesignIssues/LinkedData.html

URIs

For Linked Data, we need to be able to identify things uniquely

Uniform Resource Identifiers do this already

URIs

Using HTTP URIs is one of the principles of Linked Data

http://www.example.com/thing1

URIs

URIs are like control numbers (LCCN, ISBN, etc.).

RDF

Resource Description Framework

Written in XML

Describes relationships based on triples:

subject-predicate-object

http://www.w3.org/RDF

RDF

subject object

Charles Dickens

A Christmas

Carol

is author of

predicate

RDF statements

The subject and predicate must be URIs.

The object can be a URI or a value.

RDF

RDF is not encoded in web pages directly.

Web browsers can’t read RDF.

Software is needed to translate markup into RDF.

Ontologies

An ontology is a vocabulary of specific terms to be used to describe resources.

Sound familiar?

What could Linked Data

mean for Libraries?

Part I:What could Linked Data

mean for Library Data?

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Getting rid of silos

“Our services must not only be on the Web, but need to be of the

Web.”- Karen Coyle

RDA Vocabularies for a Twenty-First-Century Data EnvironmentLibrary Technology Reports

February 2010

Library Catalogs

World Wide Web

More open standards

Our data standards are either not used by those outside libraries (MARC)

Or not very semantically rich (Dublin Core)

But Linked Data could get us to use standards that are both of these things.

bibliographic recordsvs.

bibliographic data

In traditional cataloging, a record is one package.

Author

Title

Bibliographic Record

Bibliographic Record

Records can be exchanged, but there is no way to exchange the individual pieces of information within a record.

Bibliographic Record

Bibliographic Record

Person

Is author of

Title

Bibliographic Record

With Linked Data, a bibliographic record is made up of many pieces of data.

And the relationships between these pieces of data are defined.

Person

Is author of

Title

Bibliographic RecordThe boundaries of the record can be dissolved…

Person

Is author of

Title

Bibliographic Record…and the data can interact with other information on the Web.

Are there examples of Linked Data in

libraries?

Library of Congress Authorities and Vocabularies

http://id.loc.gov/

Library of Congress Authorities and Vocabularies

http://id.loc.gov/

RDA Metadata Registry

http://metadataregistry.org/rdabrowse.htm

Virtual International Authority File

http://viaf.org

Extensible Catalog

http://www.extensiblecatalog.org

So there’s a bunch of data out there.

Now what?

http://richard.cyganiak.de/2007/10/lod/

Library Linked Data Incubator Group

http://www.w3.org/2005/Incubator/lld/

Part II:What Could Linked Data

Mean for Librarians?

Different workflows

Catalogers could use URIs for things like authors’ names or subject headings.

If information changed, the URI could be changed and automatically update the

information in our catalogs.

Evaluating metadata

Metadata could come from various sources.

“Professional cataloging might be more of a job of aggregating and improving harvested or

contributed metadata, rather than developing new metadata, like MARC records, for

resources.”-Virginia Schilling

“The Catalogers’ Revenge: Unleasing the Semantic Web”PNLA Quarterly 74:3, 2010

New homes for librarians’ skills?

Example:The Internet Needs a Dewey Decimal System

http://www.pcworld.com/businesscenter/article/206230/the_internet_needs_a_dewey_decimal_system.html

Are There Drawbacks to Linked

Data?

Training and Software Development

“Nobody but the geekily inclined is going to be willing to invest the time and effort necessary to code semantically tagged web pages from

scratch.”

Virginia Schilling“The Catalogers’ Revenge: Unleashing the Semantic Web.”

PNLA Quarterly 74:3 (Spring 2010).

Bandwidth and Accessibility

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Metadata Standards

http://www.dlib.indiana.edu/~jenlrile/metadatamap/

Linked Data is on the horizon.

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And it has the potential to greatly change how libraries work.

Questions?

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Thank you!

Emily Dust Nimsakontemily.dust.nimsakont@nebraska.gov

http://www.delicious.com/enimsakont/linkeddata+nla2010http://www.slideshare.net/enimsakont