Dr. Sharon Yang Rider University

1. RDA and Linking Library DataVuStuff III ConferenceVillanova University, Villanova, PAOctober 18, 2012 Dr. Sharon Yang Rider University

2. Latest Development-Linked Data Model • 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. • LC at http://www.loc.gov/marc/transition/ • Graphic from http://www.w3.org/People/EM/ • LC Bibliographic Framework Transition Initiative

3. 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

4. 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

5. RDA Entity Relationships FRBR-Functional Requirements for Bibliographic Records http://www.pilin.net.au/Project_Documents/Community_Guidelines/ID_Association_Guidelines.htm

6. 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

7. 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

8. 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. Subject Object (Value)

9. Resource Description Framework The predicate must be an URL Subject must be an URI URI or text Text is a dead end; URL links; Use URIs as much as you can; create more URIs so we have URIs to link…

10. Subject, Properties, and Values Graphic from http://www.slideshare.net/iandavis/30-minute-guide-to-rdf-and-linked-dat

11. 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

12. 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

13. 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”

14. Finished Ontologies at Semanticweb.org

15. Ontologies/vocabularies Example-FOAF Worldcat linked data –example Schema.org by Google, Yahoo, Bin Open Metadata registry

16. 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/

17. 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

18. 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

19. 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

20. Questions and Answers Image from http://www.projectappleseed.org/homework.html