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

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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)

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5 Industrial relevance

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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 ?

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8 Might XML be a better solution ?

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9 Why not just XML : an example

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) 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)

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12 Resources

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13 Properties

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14 Statements

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15 The RDF data model is based on directed labelled graphs

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16 Triples with URIs

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17 RDF serialization - Turtle

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18 Namespaces and reference vocabularies

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20 Some usual vocabularies

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21 Namespaces ./.

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22 Types of triple elements

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23 Example with URIs and literals

24 Literals and datatypes

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25 Blank nodes

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26 Instances and typing

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27 Syntactic sugar

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28 The Mona Lisa example in Turtle

29 Reification

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30 Syntaxes for expressing RDF graphs

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31 The Mona Lisa example in RDF/XML ❑

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32 RDFa (RDF in HTML attributes)

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33 RDFa example

34 Application example : a review snippet from Google

[] a ns1:Product ; ns1:image ; 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

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36 Semantics of RDF graphs

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37 Semantics of RDF graphs ./.

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38 The interpolation lemma

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39 Interpolation lemma: example

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40 Agenda

1 The semantic web stack

2 Why not HTML or XML ?

3 Resource description framework

4 RDF Schema

41 Motivation for RDFS

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42 Example of a simple RDFS ontology

RDFS

43 RDFS basic ideas

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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

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46 Defining classes and instances ./.

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47 Subsumption

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48 Class hierarchy and instances

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49 Example of hierarchy with corresponding triples

50 Defining Properties

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51 Range and domain of properties

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52 Range and domain inference rules

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53 Specialization of properties

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54 Complex cases for range and domain of properties

55 Multiple range or domain statements

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57 RDFS Semantics

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58 RDFS Semantics

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59 Revisiting the example from chapter 1

60 (example after Paulheim, Semantic Web Technologies) Revisiting the example from chapter 1

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(example after Paulheim, Semantic Web Technologies) 61 Summary

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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

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64 THANK YOU

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