RDF Examples Quick Guide to RDF Syntax Nancy

RDF Examples Quick Guide to RDF Syntax Nancy Ide Vassar College Eurolan 2003 The Semantic Web and Language Technology

The RDF Description Element Attributes about refers to a URI of an existing resource ID signals the creation of a new resource <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#"> <rdf: Description about="http: //www. cs. vassar. edu/~ide/">. . . </rdf: Description> <rdf: Description rdf: ID="Nancy Ide">. . . </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

RDF Property Elements Property names must be associated with a schema Qualify property names with a namespace prefix Production property. Elt: <Property. Name> Value </Property. Name> Value = Description element or String <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="http: //www. cs. vassar. edu/~ide/rdf/"> <dc: creator>Nancy Ide</dc: creator> </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Using Abbreviated RDF Syntax Property elements converted to attributes <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="http: //www. cs. vassar. edu/~ide/ESA. pdf"> <dc: creator>Nancy Ide</dc: creator> <dc: title>Encoding Syntactic Annotation</dc: title> <dc: date>2001 -04 -10</dc: date> </rdf: Description> </rdf: RDF> <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="http: //www. cs. vassar. edu/~ide/ESA. pdf" dc: creator="Nancy Ide" dc: title="Encoding Syntactic Annotation" dc: date="2001 -04 -10"/> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Using Abbreviated RDF Syntax New fact: http: //www. cs. vassar. edu/~ide is an instance of a Web. Page rdf: type element adds this new fact value of the rdf: type can be used directly as element name <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="http: //www. cs. vassar. edu/~ide"> <rdf: type rdf: resource="http: //www. schemas. org/www/Webpage"/> <dc: creator>Nancy Ide</dc: creator> </rdf: Description> </rdf: RDF> <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/" xmlns: s="http: //www. schemas. org/www/"> <s: Web. Page about="http: //www. cs. vassar. edu/~ide"> <dc: creator>Nancy Ide</dc: creator> </s: Web. Page> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

RDF Containers Bag An unordered list of resources or literals Sequence An ordered list of resources or literals Alternative A list of resources or literals that represent alternatives for the value of a property EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Using the Bag Container Statement: The authors of the book 0201000237 are Alfred, John and Jeffrey <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="urn: ISBN: 0 -201 -00023 -7"> <dc: creator> <rdf: Bag> <rdf: li>Alfred</rdf: li> <rdf: li>John</rdf: li> <rdf: li>Jeffrey</rdf: li> </rdf: Bag> </dc: creator> </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Using the Seq Container Statement: The students of the course csci-2962 in alphabetical order are Elizabeth, George and John <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: s="http: //www. schemas. org/Course/"> <rdf: Description about="http: //www. cs. vassar. edu/courses/cs 240"> <s: students> <rdf: Seq> <rdf: li rdf: resource="http: //www. cs. vassar. edu/students/er"/> <rdf: li rdf: resource="http: //www. cs. vassar. edu/students/gl"/> <rdf: li rdf: resource="http: //www. cs. vassar. edu/students/js"/> </rdf: Seq> </s: students> </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Using the Alt Container Statement: The formats of the book 0201000237 are plain text, html and postscript <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="urn: ISBN: 0 -201 -00023 -7"> <dc: format> <rdf: Alt> <rdf: li>text/html</rdf: li> <rdf: li>text/plain</rdf: li> <rdf: li>application/postscript</rdf: li> </rdf: Alt> </dc: format> </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Making Statements about Containers <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: s="http: //www. schemas. org/Course/" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="http: //www. cs. vassar. edu/courses/cs 240"> <s: homeworks> <rdf: Bag ID="pages"> <rdf: li rdf: resource="http: //www. cs. vassar. edu/courses/cs 240/hw 1. html"> <rdf: li rdf: resource="http: //www. cs. vassar. edu/courses/cs 240/hw 2. html"> </rdf: Bag> </s: homeworks> </rdf: Description> <rdf: Description about="#pages"> <dc: creator>Nancy Ide</dc: creator> </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Making Statements about the Items in a Container <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: s="http: //www. schemas. org/Course/" xmlns: dc="http: //purl. org/dc/elements/1. 1/"> <rdf: Description about="http: //www. cs. vassar. edu/courses/cs 240"> <s: homeworks> <rdf: Bag ID="pages"> <rdf: li rdf: resource="http: //www. cs. vassar. edu/courses/cs 240/hw 1. html"> <rdf: li rdf: resource="http: //www. cs. vassar. edu/courses/cs 240/hw 2. html"> </rdf: Bag> </s: homeworks> </rdf: Description> <rdf: Description about. Each="#pages"> <dc: creator>Nancy Ide</dc: creator> </rdf: Description> </rdf: RDF> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Non-Binary Relations The RDF data model only supports binary relations (relations between two resources) Solution: Use an intermediate resource with additional properties <? xml version="1. 0"? > <rdf: RDF xmlns: rdf="http: //www. w 3. org/1999/02/22 -rdf-syntax-ns#" xmlns: s="http: //www. schemas. org/Units/"> <rdf: Description about="urn: ISBN: 0 -201 -00023 -7"> <s: price rdf: parse. Type="Resource"> <rdf: value>45. 00</rdf: value> <s: units rdf: resource="http: //www. schemas. org/Units/USdollar"/> </s: price> </rdf: Description> </rdf: RDF> Statement: The cost of the book 0201000237 is $45. 00 EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Reification Making statements about statements Classic example: “Dan Tufis says that Dan Cristea made the web page http: //www. infoiasi. ro/~cristea. ” Dan Tufis asserts Dan Cristea made http: //www. infoiasi. ro/~cristea Simple solution: Put an rdf: ID attribute on the property element. By default, anything with an rdf: ID is an instance of RDF: Statement EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

The parse. Type attribute Use attribute parse. Type="Resource" on an RDF/XML element when there is an rdf: Description (or its equivalent) as a child element <rdf: Description about="urn: ISBN: 0 -201 -00023 -7"> <s: price rdf: parse. Type="Resource"> <rdf: value>45. 00</rdf: value> <s: units rdf: resource="http: //www. schemas. org/Units/USdollar"/> </s: price> </rdf: Description> Use attribute parse. Type=”Literal” on an RDF/XML element when the content is not to be parsed by the RDF parser <dc: title rdf: parse. Type="Literal"> Solving <mrow><msup><mi>x</mi><mn>2</mn></msup><mo>+</mo><mn>1</mn></mrow> <mo>=</mo><mn>0</mn> </mrow> </dc: title> EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania

Exercise Get your hands dirty with some real RDF. . . Create an RDF schema for EAGLES morpho-syntactic categories Extend to your own language, using the EAGLES specifications Tag some text? Use Protoge, a simple RDF editor, or a plain text editor EUROLAN 2003 THE SEMANTIC WEB AND LANGUAGE TECHNOLOGY July 28 - August 8, Bucharest - Romania