Is Semantic Web Our Future? Computers in Libraries Conference 2012

March 21-23, 2012Hilton Washington

Washington, DC

Sharon Q. Yang, Rider University, NJ Yan Yi Lee, Wagner College, NYC

What is Semantic Web?

• A vision by Tim Berners-Lee, Director of World Wide Web Consortium, in late 1999• Web 3.0, Giant Global Graph, Web of linked

data, a web of data• An extension of current Web, not a replacement• “A web of data that can be processed directly and indirectly by machines” –

Tim Berners-Lee

*Photo of Tim Berners-Lee in 2005 from Wikipedia

Three Things to Remember about Semantic Web

1. Machines understand/process data 2. Entity relationships (RDA is also about entity relationships)

– Relationships between humans and things – properties of humans and things (attributes and values)

3. A Web of linked data vs. a Web of linked documents

Demos of Semantic Web Applications

• Hakia at http://www.hakia.com (a semantic Search engine)• Friend of A Friend at http://www.foaf-search.net/• LIBRIS Swedish Union Catalog at

http://libris.kb.se/index.jsp?language=en• Isearch at http://www.isearch.com/?refer=3338• Dbpedia at http://dbpedia.neofonie.de/browse/• Notable Names Database at www.NNDB.com

A Word May Have Many Meanings…

• I love Boston-Which of the 26 Bostons in the world?• UC Berkeley –People write it in 50 different ways on

the Internet (Metaweb Inc . at http://wiki.freebase.com/wiki/Main_Page)

• A single entity?• A single entity vs. text of different meanings and

spellings• A single entity is a thing, place, person, concept,

object or anything

Uniform Resource Identifier (URI)

• An entity may be represented by URI in Semantic Web• An entity is also called a resource • Examples of URI from LCSH in SKOS

– Example of URI - Shakespeare– Example of URI – 911 Terrorist attacks– Example of URI- Semantic Web

• URI is am important basic building block in linking data

Resource Description Framework (RDF)-Entity Relationship Model

RDF statements are often referred to as “triples” that consist of a subject, predicate, and object, which correspond to a resource (subject), a property (predicate), and a property value (object).

RDF Triples

• Subject – an entity (can be a URI)• Predicate -property or attribute (can be a URI)• Object – a property value (can be a URI)• Examples:

– New York-- is place of publication of --Raintree County– Viking Penguin-- is publisher of --Raintree County– 1994-- is date of publication of-- Raintree County (Caren Koyle “Library Data in the

Web World”)

– T-shirt –color-red• Languages: RDF/XMS, N3, Turtle, N-Triples, Json

RDF/XML

”The Secret Agent” is written by Joseph Conrad

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:lib="http://www.zvon.org/library">

<rdf:Description about="The Secret Agent"> <lib:creator>Joseph Conrad</lib:creator> </rdf:Description> </rdf:RDF>

Is created by

*RDF Tutorial at http://zvon.org/xxl/RDFTutorial/General/contents.html

http://library.rider.edu/books/TheSecretAgent http://www.nndb.com/JosephConrad

Share and Link Data?

MySQl MS SQL Oracle

Interoperability and Cross Domain Sharing

Shared Base Ontology and

Common Vocabulary

Database 1 Database 2 Database 3

Vocabularies and Ontologies

• Vocabulary - A collection of terms given a well-defined meaning that is consistent across contexts.

• Ontology - Allows you to define contextual relationships behind a defined vocabulary. It is the cornerstone of defining a knowledge domain. (Semantic Modeling Tutorial at www.linkeddatatools.com)

Semantic Web Ontologies

• “An ontology is a formal specification of a shared conceptualization”1

• “the success of the semantic Web depends predominantly on the proliferation of ontologies…” 2

• Different domain has different ontology

• Ontologies are written in Web Ontology Language (OWL) and RDFS (RDF Schema) and others.

1. Tom Gruber at http://www-ksl.stanford.edu/kst/what-is-an-ontology.html2. Kaushal Girl “Role of Ontology in Semantic Web”

Finished Ontologies

Illustration

Name Workplace Interest

Sharon Yang Lawrenceville Linked data

Institution Location Type

Rider US University

Database 1Database 2

More on Ontology

Place

Workplace

Location

Lawrenceville

United States

RDFS: subClassOf

RDFS: subClassOf

RDF: type

RDF: type

P:subdivisonName

Person

Institution

Has

works for University Is

Has

Power of Inference in Semantic Web

• Inference establishes new relationships• Example – Tom is a cat – Every cat is a mammal (defined in ontology)– Tom is a mammal

Advantages of Joining Semantic Web

•Bibliographical data is now stored in databases and not searchable on the Web. •Silos, invisible Web, dark Web, deep Web, hidden Web•Releasing bibliographical data and displaying it on the Internet•Searching and retrieval by semantic relationships•Shared standards and data models with the rest of the world•Data exchange with other metadata communities

Semantic Web Development in Libraries

• RDA Vocabulary & OMR (JSC/CDMI/ALA) • MulDiCat (IFLA)• Authorities and Vocabularies (LC)• Linked Data Research (OCLC Research Projects)

RDA Vocabularies and OMR

• RDA (Resource Description and Access) - New Cataloging Rules, released in 2009

- US National Libraries RDA Test, July 2010 March 2011 ̴ - Implementation, March 31, 2013

- Based on FRBR, FRAD standards, Entity-Relationship - Build Semantic Web enabled vocabularies• RDA Vocabularies published in OMR (Open Metadata

Registry)

RDA Vocabularies and OMR - continued

• OMR – Open Metadata Registry - Formerly founded by NSDL (National Science Digital Library) - Currently managed by Metadata Management Associates - Available openly to anyone who wish to use the service - Used by the resource description community - Used by Semantic Web developers - Goals: Metadata discovery Reuse Standardization Interoperability

RDA Vocabularies and OMR - continued

• RDA Vocabularies published in OMR, 2011 2012 ̴ - DCMI/RDA Task Group - JSC for development of RDA - ALA (Co-Publisher of RDA)• Base Domain: http://rdvocab.info/• Data model: SKOS (Simple Knowledge Organization System)• Stand model: RDF

RDA Vocabularies and OMR - continued

RDA Vocabularies and OMR - continue

RDA Vocabularies and OMR - continue

RDA Vocabularies and OMR - continue

“The Committee is committed to publishing and maintaining the content of the RDA vocabularies, synchronized with the text of RDA, in order to support their use by the resource description community and by developers of Semantic Web applications” – Alan Danskin, 2011 (Chair of JSC, 2009 – 2011)

“The RDA vocabularies represent many decades of library experience and practice which is now shared with the rest of the world.” - Gordon Dunsire, 2011 (co-Chair of the DCMI/RDA Task Group)

MulDiCat

• MulDiCat – Multilingual Dictionary of Cataloging Terms and Concepts

- MulDiCat Working Group, IFLA Cataloging Section - Definitions for terms and concepts used by catalogers - In 27 different languages (will be more) - Authoritative translations of IFLA cataloging standards - Store in IFLA namespace as a SKOS file - IFLA Namespaces - iflastandards.info

MulDiCat - continued

Authorities and Vocabularies

• Library of Congress Authority Data in SKOS• Delivered as Linked-Data• Accessible for both human and machine• Visualization of relationships between concepts and

values• id.loc.gov

Authorities and Vocabularies - continued

Include - LC Subject Headings - LC Name Authority File - LC Children’s Subject Headings - Genre/Form Terms - Thesaurus of Graphic Materials ……

Authorities and Vocabularies - continued

Linked Data Research

• OCLC Linked Data Research - Identify things via URIs

- Improve discovery • Related research projects - FAST (Faceted Application of Subject Terminology)

- VIAF (The Virtual International Authority File)

FAST

• FAST – Faceted Application of Subject Terminology - An experimental Linked Data service by OCLC - Adapt LCSH with simplified syntax - Easy to understand, apply, and use - Data model: SKOS - FAST Linked Data http://experimental.worldcat.org/fast/

FAST - continued

Link to LCSH at id.loc.gov

VIAF

• VIAF – The Virtual International Authority File - International Joint project (LC, German National

Library, National Library of France, etc.) - A single authority service - combined 21 name

authority files from 18 organizations around the world

- Hosted in OCLC http://viaf.org - Plays a role in Semantic Web

VIAF - continued

Giant Graph (Wikipedia)

Giant Graph (Wikipedia)

Is Semantic Web Our Future? Food for Thought…

Image from http://www.projectappleseed.org/homework.html