Semantic WebExam 1 Review

Agenda

•URI•XML•RDF•RDF/XML•RDFS•SPARQL•Reification•Design Patterns

URI Jargon Summary

soap://www.visa.com/CreditCardService#

URI ContextURISchemeName:schemeSpecificPart

SchemeName Scheme Specifics Part

XMLNS ContextQualified Name (QName) – as text macro for entity and attribute names!ENTITY ContextText macro for attribute values (dereference with &;)

QName

URI Jargon SummaryValid URI ExamplesURISchemeName:schemeSpecificPart

urn:monterey#1sc:johnnyhttp://utdallas/semclass#

XML structure

•XMLNS scope and effect•!ENTITY usage•Entity, attribute, content•Reading RDF/XML

RDF & RDF/XML• Verbs (properties) defined in RDF

▫ Usage and meaning• Reading RDF/XML

▫ How many triples?▫ What graph structure?▫ Classes, properties, and short-cuts

• Limitations of RDF and RDF/XML for semantic web needs

• Writing RDF/XML statements▫ Point to a literal▫ Point to an existing resource (i.e. rdf:resource)

RDF & RDF/XML

•Draw graph from RDF/XML and N3 data▫Resources as circles/ellipses and literals as

boxes.▫Short labels in each shape and on lines▫Bring a pencil if you have trouble making

figures with pen•Note that containers include a rdf:type

node and use _1, _2, etc▫Collections do not use a type node and use

‘first’, ‘rest’, and nil

RDFS

•Verbs (properties) defined in RDFS▫Emphasis on:

subClassOf and subPropertyOf domain and range

•Transitive relationships

RDF/RDFS Example<?xml version="1.0"?><!DOCTYPE rdf:RDF [<!ENTITY exterms "

http://www.example.org/terms/">]> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:exterms="http://www.example.org/terms/" xmlns:other="uri:"> <rdfs:Property rdf:about="&exterms;creation-date">

<rdf:Description rdf:about="http://www.example.org/index.html"> <exterms:creation-date>August 16, 1999</exterms:creation-date> <dc:language>en</dc:language> <dc:creator rdf:resource="http://www.example.org/staffid/85740"/> </rdf:Description>

<rdf:Statement> <rdf:subject rdf:resource=" http://www.example.org/index.html"/> <rdf:predicate rdf:resource=“&exterms;creation-date"/> <rdf:object>August 16, 1999</rdf:object> <dc:creator>"Stewart"</dc:creator>

<other:creatorConfidenceInFact>"95%"</other:creatorConfidenceInFact> </rdf:Statement>

</rdf:RDF>

Creation-date is a property. (Makes a triple)

Stewart claims he knew the creation date and his confidence in it.

This “Statement” (i.e. reification) is a blank node

SPARQL• Writing SPARQL SELECT queries

▫ Query for all triples• Blank node handling and meaning

▫ Handling containers - Query for one or more specific elements off the container (hint: use UNION)

• Text macros▫ BASE, PREFIX

• Handling containers and collections• Named Graphs and default graph• Use of UNIONEspecially consider Sparql_PopQuizAndInClassLab.ppt

Reification

•Meaning of reification ▫Reification class type and required

properties▫Meaning of metadata from reification node▫Meaning of multiple reification nodes

Design Patterns• Pattern Categories

▫ Architectural vs Design vs Idioms

• For patterns presented▫ The need for the

pattern▫ The foundational idea

of the pattern▫ Specifically info in Lecture

4 – SubsetOfHeadsUpPatterns.ppt

Architectural pattern

Design Pattern

Idiom

Factory Method Singleton Object Pool

Composite Decorator Observer

Strategy Template Method

Ontologies

•VCARD▫For personal business cards (pretty much

contact info)•Dublin Core

▫For basic metadata – creators, dates, scope of creations/entities

•FOAF▫For friendships, working relationships to

others, organizations, and groups

Not covering

•New material presented from Ch 10 and 11 (i.e. OWL)

•New material presented in Ontology Design 101

•Jena specifics•UML and Lecture 6 design patterns