Introduction to Linked Data Discussion #1 | University of Texas at Austin | August 13, 2018 Facilitated by: Itza A. Carbajal, LLILAS Benson Latin American Metadata Librarian Hello! My name is Itza A. Carbajal I will be facilitating this discussion series on Linked Data I am the Latin American Metadata Librarian for a Post Custodial project at LLILAS Benson Have questions? Email me at: [email protected] Like twitter? You can find me at: @archiviststan Housekeeping ◎ Discussions are meant to highlight collective wisdom of the group ◎ Attendance to all discussion meetings not required, but recommended ◎ Take home practices are not required, but encouraged to further an individual’s understanding ◎ Readings are not required, but should be considered as a method for self education or for sharing with others Link to LIVE syllabus: http://bit.ly/SYLLABUSUTLD Link to reading materials: http://bit.ly/READUTLD 1. Discussion #1 Topics Topics to Discuss ◎ Semantic Web ◎ Linked data principles ◎ RDF and Triple statements Related Topics not covered in discussions ◎ Linked Open Data ◎ Examples of linked open data sets ◎ Linked Data platform 2. First, the Semantic Web Semantic Web (project) ◎ Derives from the concept of semantics defined as the study of meanings ◎ Extension to the current World Wide Web ◎ Also known as Web 3.0 where the web can now “read-write-execute” ◎ Changes the current web of information to a web of data including data inside the web and outside ◎ Core functions include semantic markup ○ Semantic markup - data interchange formats accessible to humans and machine ◎ Focuses on adding meaning/context to information giving machines and humans the ability to communicate and cooperate ◎ Relies on machine-readable metadata to expresses that meaning/context ◎ No formal definition, still ongoing and constantly maturing 3. Now, Linked Data Principles Linked Data Principles (as noted by Tim Berners-Lee) ◎ Use Uniform Resource Identifiers (URIs) as names for things ○ URIs are assigned to resources to provide persistency and flexibility and are ideally independent of underlying location ◎ Use HTTP URIs so that people can look up those names ○ URIs are formed using the Hypertext Transfer Protocol (HTTP) ◎ When someone looks up a URIs, linked data should provide useful information using the standards (RDF, SPARQL) ◎ Include links to other URIs, so that people can discover more things 4. Finally, RDF & Triples Resource Description Framework (RDF) ◎ Common framework model that uses multiple technologies to implement linked data principles on the semantic web using statements ◎ Expresses linked data by specifying relationships between things thus sharing information in the web and those not directly found on the web ◎ These relationships help humans and machine navigate between or integrate information from different and multiple sources ◎ Supports changes to schemas without drastic changes to the data ◎ Allows for structures and semi-structured data to combined, exposed, and shared across the web and online applications ◎ Uses a variety of syntax notations and data serializations such as Turtle, Notation 3 (N3), RDF/XML, and JSON-LD, RDFa, and N-Triples (the list continues to grow and decisions on use depend on the intent) Semantic Triple ◎ Also referred to as simply a triple or triple statement ◎ Data entity and the building block of RDF ◎ Comprised of SUBJECT -- PREDICATE -- OBJECT ○ think three equals a triple ◎ A collection of triples is stored in a database called a Triplestore ○ use semantic queries with the query language of SPARQL to retrieve triples subject predicate object RDF Graph ◎ Visual element of RDF ◎ Is a technology used in generating visual RDF statements ◎ Can represent a set of triples (think 2 sets or 1000s) ◎ Of the triple elements ○ Subjects and objects are called nodes ○ Predicates represent the arch (connection between subject and object) with arrow point from subject to object Linked Open Data Cloud, September 2011 4. Hands on Activity “ Consider yourself a “resource” with your name as the URI. How would you create a triple statement using the resource (your identity) as the subject to describe yourself? EXAMPLE scooter Metadata librarian works as drives Itza likes drinks coffee cats WRAP UP TAKE HOME PRACTICE: Create triple statement(s) using the designated “Resource” as the subject Discussion #2 Details DATE: August 27, 2018 TIME: 9:30 am PLACE: PCL 1.340 Link to LIVE syllabus: http://bit.ly/SYLLABUSUTLD References Allemang, Dean & Hendler, Jim. (2011). Semantic Web for the Working Ontologist. 2nd ed. Amsterdam: Elsevier. Berners-Lee, Tim. Architecture. World Wide Web Consortium. Downloaded July 28, 2018 from: http://www.w3.org/2000/Talks/1206-xml2k-tbl/slide10-0.html Hart, Glen & Dolbear, Catherine. (2013). Linked Data: A Geographic Perspective. Boca Raton: CRC Press. Klyne, Glenn & Carroll, Jeremy J.(editors). Resource Description Framework (RDF): Concepts and Abstract Syntax. Copyright 2004 World Wide Web Consortium, (Massachusetts Institute of Technology, European Research Consortium for Informatics and Mathematics, Keio University). Accessed July 28, 2018 from http://www.w3.org/Consortium/Legal/2002/copyright-documents-20021231 Tauberer, Joshua. (2008, January). What is RDF and what is it good for? Downloaded July 28, 2018 from http://www.rdfabout.com/intro/ . W3C. Schreiber, Guus & Raimond (editors). RDB 1.1 Primer. Downloaded July 28, 2018 from http://www.w3.org/TR/rdf11-primer/ . "W3C Semantic Web Frequently Asked Questions." Extensible Markup Language (XML) 1.0 (Fifth Edition). November 12, 2009. Accessed August 6, 2018. https://www.w3.org/RDF/FAQ..