RDA and Linking Library DataVuStuff III Conference

Villanova University, Villanova, PAOctober 18, 2012

Dr. Sharon Yang

Rider University

Latest Development-Linked Data Model

• LC Bibliographic Framework Transition Initiative

• On May 22, 2012 -“translate the MARC 21 format to a Linked Data (LD) model”1

• LC contracted Zepheira to help the process headed by Eric Miller2

• The Linked Data (LD) model will serve as the starting point for further discussion and revisions.

1. LC at http://www.loc.gov/marc/transition/

2. Graphic from http://www.w3.org/People/EM/

A Word May Have Many Meanings…

• I love Boston-Which of the 26 Bostons in the world?1

• UC Berkeley –People write it in 50 different ways on the Internet.2

• Apple (fruit) vs. Apple (computer)

• Kings-monarchs, the hockey team, the basketball team or the TV series?3

1 & 2 - Metaweb Inc . at http://wiki.freebase.com/wiki/Main_Page

3. http://www.readwriteweb.com/archives/google-goes-back-to-what-it-does-well-finding-things.php?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+readwriteweb+%28ReadWriteWeb%29&utm_content=Google+Reade

4. Graphic from http://www.accountingweb.com/image/confusedstumpeduncertain

The Solution Is …

• Map words to things (or entities)• An entity is a thing, place, person, concept, object or

anything• An entity (a description of an entity) on the Web is

called a resource • URI (Uniform Resource Identifier) identifies a unique

resource• One resource/entity links to more resources/entities

through relationships• RDA is based on entities and their relationships

RDA Entity Relationships

FRBR-Functional Requirements for Bibliographic Records

http://www.pilin.net.au/Project_Documents/Community_Guidelines/ID_Association_Guidelines.htm

So Here is the Linked Data Model…

• Tim-Burners Lee’s principles in 20061 and 2009– Use URIs as names for things (Uniform Resource Identifier)– Use HTTP URIs so that people can look up those names– When someone is looking up an URI, provide useful information– Include links to other URIs that lead to other related information on the Web

1. http://www.w3.org/DesignIssues/LinkedData.html

URI (Uniform Resource Identifier)

• An URI (URL) uniquely and globally identifies a resource on the Web

• 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

Predicate (Property)

RDF is the data format for linked data

RDF statements are called triples

RDF is about writing down relationships between entities.

SubjectObject (Value)

Resource Description Framework

Subject must be an URI

URI or text

The predicate must be an URL

Text is a dead end; URL links; Use URIs as much as you can; create more URIs so we have URIs to link…

Subject, Properties, and Values

Graphic from http://www.slideshare.net/iandavis/30-minute-guide-to-rdf-and-linked-dat

RDF Triples

• Subject – an entity (must be a URI)• Predicate -property or attribute (must a URI)• Object – a property value (can be a URI or text)• More examples:

– Humans-property (gender)-value (M/F)– Clothes-property (color)-value (red, green, yellow,

orange)

• Semantic languages: RDF/XML, N3, Turtle, N-Triples, Json

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.1

• Library vocabularies

1. 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.html

2. Kaushal Girl “Role of Ontology in Semantic Web”

Finished Ontologies at Semanticweb.org

Ontologies/vocabularies

Example-FOAF

Worldcat linked data –example

Schema.org by Google, Yahoo, Bin

Open Metadata registry

Power of Inference in Semantic Web

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

Graphic from http://venturebeat.com/2009/04/13/semantic-answer-engine-true-knowledge-opens-to-developers/

Linked Data

• URI identifies a unique resource/things/entities on the Web

• RDF establishes relationships between entities• Semantic inference establishes more relationships• Millions/billions/trillions of RDF triples • The Web is one big database in RDF format

pointing to URIs which lead to more URIs• Linked data is a graph database (graph data)• Subject services/applications (SPARQL) searches

URIs and display data

Linked Data1

• If two people creating data use the same URI, then they describe the same thing.

• Merge data from different Web sites• Power of inference• Assemble more information about entities by

following links• Subject applications/subject services• SPARQL is the query language to do this

• 1. http://www.slideshare.net/iandavis/30-minute-guide-to-rdf-and-linked-data

Web of Data vs. Web of HTML Docs

• OCLC Worldcat.org /demo• Google Knowledge Graph• Friend of A Friend at http://www.foaf-search.net/• Isearch at http://www.isearch.com/?refer=3338• Dbpedia at http://dbpedia.neofonie.de/browse/• BBC Nature Wildlife • Swedish Union Catalog• Hakia

Questions and Answers

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