openhpi 1.4 - the limits of the web (continued)

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 04: The Limits of the Web (continued)

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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04: The Limits of the Web (continued) OpenHPI - Course Semantic Web Technologies - Lecture 1: The Web of Data

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

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

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Problem 1: Information Retrieval

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

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Problem 1: Information Retrieval

•traditional keyword-based search leads to many not relevant results•different meanings•polysemy•different contexts

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

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Problem 1: Information Retrieval

•traditional keyword-based search does not find all results•synonyms and metaphors•missing context definition

Jaguar

Panthera Onca

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

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Problem 2: Information Extraction

What does the information mean?

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

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Problem 2: Information Extraction

What does the information mean?

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

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Problem 2: Information Extraction

Information Extraction•can only be solved ,correctly‘ by a human agent

•heterogeneous distribution and order of information

•Software agent does not have sufficient

•knowledge of contexts

•world knowledge and

•experience

•to solve the problem

Problemfeld 2: Informationsextraktion

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•implicit knowledge, i.e. information does not have specified explicitely, but must be derived via logical deductions from available information.

Problem 2: Information Extraction

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

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Problem 3: Maintenance

•the more complex and voluminous a website, the more complicated is the maintenance of the only weakly structured data.

•Problems:•syntactic and semantic (link)

consistency•correctness•timeliness

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

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Problem 4: Personalization

•Adaption of the presented information content to personal requirements

•Problems: •from where do we get the

required (personal) information?

•personalization vs. data security

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

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GAME OVER

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

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