Semantic Data Chapter 3 : The semantic web resource description framework Jean-Louis Binot 1 Semantic Data 17/02/2021 Course content outline 2 Sources and recommended readings ❑ ◼ ❑ ◼ ◼ ◼ ❑ ◼ ◼ ◼ 3 Agenda 1 The semantic web stack 2 Why not HTML or XML ? 3 Resource description framework 4 RDF Schema 4 The semantic web standards (W3C consortium) ❑ ◼ ❑ ◼ ❑ ◼ ❑ ❑ 5 Industrial relevance ❑ ❑ ◼ ◼ ◼ ◼ ◼ ◼ 6 Agenda 1 The semantic web stack 2 Why not HTML or XML ? 3 Resource description framework 4 RDF Schema 7 Why not just HTML ? ❑ ❑ ❑ ❑ 8 Might XML be a better solution ? ❑ ◼ ◼ ◼ ❑ ◼ ❑ 9 Why not just XML : an example ❑ ❑ ❑ ◼ ◼ ) lecturer 10 Agenda 1 The semantic web stack 2 Why not HTML or XML ? 3 Resource description framework 4 RDF Schema 11 Basic ideas of the Resource Description Framework (RDF) ❑ ❑ ❑ 12 Resources ❑ ◼ ◼ ◼ ❑ ◼ ◼ 13 Properties ❑ ◼ ❑ ❑ ◼ ◼ 14 Statements ❑ ◼ ❑ ◼ ❑ 15 The RDF data model is based on directed labelled graphs ❑ ❑ ❑ 16 Triples with URIs ❑ ◼ ◼ ◼ ◼ ❑ 17 RDF serialization - Turtle ❑ ◼ ❑ ◼ ❑ 18 Namespaces and reference vocabularies ❑ ❑ ◼ ◼ ◼ ◼ ❑ 19 ❑ ❑ 20 Some usual vocabularies ❑ ❑ 21 Namespaces ./. ❑ ❑ ❑ ❑ 22 Types of triple elements ❑ ◼ ◼ ◼ ❑ ◼ ✓ ✓ ✓ ◼ ✕ ✕ ✓ ◼ ✓ ✕ ✓ 23 Example with URIs and literals 24 Literals and datatypes ❑ ❑ ◼ ◼ ◼ ❑ ◼ ◼ 25 Blank nodes ❑ ◼ ◼ ❑ 26 Instances and typing ❑ ❑ ❑ 27 Syntactic sugar ❑ ❑ ❑ 28 The Mona Lisa example in Turtle 29 Reification ❑ ❑ ◼ ◼ ❑ 30 Syntaxes for expressing RDF graphs ❑ ❑ ◼ ❑ ◼ ❑ 31 The Mona Lisa example in RDF/XML ❑ ❑ 32 RDFa (RDF in HTML attributes) ❑ ❑ ◼ ◼ ◼ ◼ ❑ ❑ 33 RDFa example 34 Application example : a review snippet from Google [] a ns1:Product ; ns1:image <catcher-in-the-rye-book-cover.jpg> ; ns1:name "The Catcher in the Rye" ; ns1:review [ a ns1:Review ; ns1:author [ a ns1:Person ; ns1:name "John Doe" ] ; ns1:datePublished "2006-05-04" ; ns1:name "A masterpiece of literature" ; ns1:publisher [ a ns1:Organization ; ns1:name "Washington Times" ] ; ns1:reviewBody "I really enjoyed this book. It captures the essential challenge people face as they try make sense of their lives and grow to adulthood." ; ns1:reviewRating [ a ns1:Rating ; ns1:ratingValue "5" ] ] . 35 Formal semantics of RDF ❑ ❑ ◼ ❑ ◼ ❑ ◼ ◼ 36 Semantics of RDF graphs ❑ ◼ ◼ ❑ ◼ ◼ ◼ ◼ ∃ ∧ 37 Semantics of RDF graphs ./. ❑ I I I ◼ I ◼ I I ◼ ◼ ⊨ ◼ 38 The interpolation lemma ❑ ◼ ❑ ◼ ◼ ❑ ◼ ⊨ ◼ 39 Interpolation lemma: example ❑ ⊨ ◼ ❑ ⊭ ❑ ◼ 40 Agenda 1 The semantic web stack 2 Why not HTML or XML ? 3 Resource description framework 4 RDF Schema 41 Motivation for RDFS ❑ ❑ ◼ ❑ ❑ 42 Example of a simple RDFS ontology RDFS 43 RDFS basic ideas ❑ ◼ ◼ ◼ ◼ ❑ ❑ ◼ http://www.w3.org/2000/01/rdf-schema#> 44 RDFS main constructs Construct (construct type) Syntactic form Description Class (a class) C rdf:type rdfs:Class C (a resource) is an RDFS class Property (a class) P rdf:type rdf:Property P (a resource) is an RDF property type (a property) I rdf:type C I (a resource) is an instance of C (a class) subClassOf (a property) C1 rdfs:subClassOf C2 C1 (a class) is a subclass of C2 (a class) subPropertyOf (a property) P1 rdfs:subPropertyOf P2 P1 (a property) is a sub-property of P2 (a property) domain (a property) P rdfs:domain C domain of P (a property) is C (a class) range (a property) P rdfs:range C range of P (a property) is C (a class) 45 Defining classes and instances ❑ ❑ 46 Defining classes and instances ./. ❑ ❑ ◼ ◼ ❑ 47 Subsumption ❑ ❑ ∧ ❑ 48 Class hierarchy and instances ❑ ∧ ❑ 49 Example of hierarchy with corresponding triples 50 Defining Properties ❑ ❑ ❑ 51 Range and domain of properties ❑ ❑ 52 Range and domain inference rules ❑ ∧ ❑ ∧ ❑ 53 Specialization of properties ❑ ❑ ∧ 54 Complex cases for range and domain of properties 55 Multiple range or domain statements ❑ ❑ ❑ 56 ❑ ❑ ◼ ◼ ◼ ❑ ◼ ◼ 57 RDFS Semantics ❑ → → → → 58 RDFS Semantics ❑ ◼ ◼ ◼ ❑ ◼ ◼ 59 Revisiting the example from chapter 1 60 (example after Paulheim, Semantic Web Technologies) Revisiting the example from chapter 1 ✓ ✓ ✓ ✗ ✗ ✗ ❑ (example after Paulheim, Semantic Web Technologies) 61 Summary ❑ ❑ ❑ ❑ ❑ 62 Annex : RDF/RDFS entailment patterns If S contains: then S RDF(S)_entails : rdfD1 a p "v"^^d . a p _:b . _b rdf:type d . rdfD2 a p b . p rdf:type rdf:Property . rdfs1 any IRI a in D a rdf:type rdfs:Datatype . p rdfs:domain x . rdfs2 a rdf:type x . a p b . p rdfs:range x . rdfs3 b rdf:type x . a p b . rdfs4a a p b . a rdf:type rdf:Resource . rdfs4b a p b . b rdf:type rdf:Resource . p rdfs:subPropertyOf q . rdfs5 p rdfs:subPropertyOf r . q rdfs:subPropertyOf r . rdfs6 a rdf:type rdf:Property . a rdfs:subPropertyOf a . rdfs:subPropertyOf q . rdfs7 a q b . a p b. rdfs8 c rdf:type rdfs:Class . c rdfs:subClassOf rdf:Resource . c rdfs:subClassOf d . rdfs9 a rdf:type d . a rdf:type c. rdfs10 c rdf:type rdfs:Class . c rdfs:subClassOf c . c rdfs:subClassOf d . rdfs11 c rdfs:subClassOf e . d rdfs:subClassOf e . rdfs12 rdf:type rdfs:ContainerMembershipProperty . p rdfs:subPropertyOf rdfs:member . rdfs13 d rdf:type rdfs:Datatype . d rdfs:subClassOf rdfs:Literal . 63 References ❑ ❑ 64 THANK YOU 65.