Dr. Harald Sack

Hasso Plattner Institute for IT Systems Engineering

University of Potsdam

Spring 2013

Semantic Web Technologies

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Lecture 1: The Web of Data 05: The Vision of the Semantic Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

Lecture 1: The Web of Data

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Open HPI - Course: Semantic Web Technologies

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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05: The Vision of the Semantic Web OpenHPI - Course Semantic Web Technologies - Lecture 1: The Web of Data

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Tim Berners-Lee, Semantic Web Roadmap, Sept 1998

„The Web was designed as an information space, with the goal that it should be useful not only for human-human communication, but also that machines would be able to participate and help… “

From the World Wide Web to the Web of Data

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

5Precondition:• Content can be read and

interpreted correctly (= „understood“) by machines

Natural Language Processing• Technologies of traditional

Information Retrieval (Search Engines)

From the World Wide Web to the Web of Data

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Semantic Web• Natural language web content will

be explicitly annotated with semantic metadata

• Semantic metadata encode the Meaning (Semantics) of the content and can be read and interpreted correctly by machines

From the World Wide Web to the Web of Data

Precondition:• Content can be read and

interpreted correctly (= „understod“) by machines

Natural Language Processing• Technologies of traditional

Information Retrieval (Search Engines)

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Text: „Why snub me, Fab?“

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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• Disambiguationsolution of linguistic ambiguities

Text: „Why snub me, Fab?“

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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• Disambiguationsolution of linguistic ambiguities

Text: „Why snub me, Fab?“

Fabio Capello ?

Entity MappingDisambiguation

FAB ?

FAB ?

Manager of the UK national Football team

the Film Advisory Board

Federación Atlética de Bolivia

Fab Melo ? Brazilian Basketball Player

Fab ? a detergent

Fab ? a Canadian gay magazine

Fabrizio Moretti ? Drummer of The Strokes

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello

Entity Mapping

Entity

• The Meaning (Semantics) of entitiesand classes must be defined explicitly.

Text: „Why snub me, Fab?“

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello

Entity Mapping

Entity

Soccer Manager

is a

Class

• The Meaning (Semantics) of entitiesand classes must be defined explicitly.

Text: „Why snub me, Fab?“

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello

Entity Mapping

Entity

Soccer Manager

is a

Class

Person

is subclass of

Class

• The Meaning (Semantics) of entitiesand classes must be defined explicitly.

Text: „Why snub me, Fab?“

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello (entity)

Soccer Manager

is a

(class)

Class-membership has class

•The Meaning (Semantics) is expressed with the help of appropriate knowledge representations (Ontologies)

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

11

Fabio Capello (entity)

Soccer Manager

is a

(class)

Class-membership has class

Person

is subclass of

(class)

superclass

subclass

is subclass of

•The Meaning (Semantics) is expressed with the help of appropriate knowledge representations (Ontologies)

„Understanding“ Content on the Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello

Soccer Manager

Person

is aEntities

Classes

is subclass of

„Understanding“ Content on the Web (III)

•The Meaning (Semantics) is expressed with the help of well suited knowledge representations (Ontologies)

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello

Soccer Manager

Person PlacebirthPlace

is aEntities

Classes

is subclass of

„Understanding“ Content on the Web (III)

•The Meaning (Semantics) is expressed with the help of well suited knowledge representations (Ontologies)

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Fabio Capello

Soccer Manager

Person PlacebirthPlace

is aEntities

Classes

is subclass of

San CanzianbirthPlace

is a

„Understanding“ Content on the Web (III)

•The Meaning (Semantics) is expressed with the help of well suited knowledge representations (Ontologies)

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

12

Fabio Capello

Soccer Manager

Person PlacebirthPlace

DatebirthDate

is aEntities

Classes

is subclass of

San CanzianbirthPlace

is a

„Understanding“ Content on the Web (III)

•The Meaning (Semantics) is expressed with the help of well suited knowledge representations (Ontologies)

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

12

Fabio Capello

Soccer Manager

Person PlacebirthPlace

DatebirthDate

is aEntities

Classes

is subclass of

San CanzianbirthPlace

is a

birthDate1946-06-18

is a

„Understanding“ Content on the Web (III)

•The Meaning (Semantics) is expressed with the help of well suited knowledge representations (Ontologies)

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Tim Berners-Lee, James Hendler, Ora Lassila: The Semantic Web, Scientific American, 284(5), pp. 34-43(2001)

What is the Semantic Web?

„The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation"

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

14•The Meaning of Information (Semantics) is made explicit by

formal (structured) and standardized knowledge representations (Ontologies).

• Thus it will be possible,

•to process the meaning of information automatically

•to relate and integrate heterogeneous data

•to deduce implicite (not evident) information from existing (evident) information in an automated way

The Semantic Web is kind of a global database that contains a universal network of semantic propositions.

The Semantic Web - a Web of Data

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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Das Semantic Web

•

Semantic Web ...towards an „intelligent“ Web

Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

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06: The Vision of the Semantic Web Pt.2 OpenHPI - Course Semantic Web Technologies - Lecture 1: The Web of Data

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