1 Copyright 2008 Digital Enterprise Research Institute. All rights reserved.

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From OntoSelect to OntoSelect-SWSE

Paul Buitelaar, Andreas HarthDERI – NUIG, Galway

February 2009

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Outline

OntoSelect @ DFKI Recap of OntoSelect Functionality

OntoSelect @ DERI SWSE: Semantic Web Search Engine Architecture OntoSelect-SWSE

OntoSelect-SWSE Experiments Ranked List of Ontologies with Rich Metadata

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OntoSelect

Ontology Library and Ontology Search Service

http://olp.dfki.de/OntoSelect

OntoSelect monitors the web for ontologies (indexing/updates) Ontology browse and search (by keyword, topic, document) Class, property and (multilingual) label browse and search Ontology publishing (submit your ontology) Statistics on

– Formats– Human languages– Frequently used labels– Ontology publishing

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Browse Ontologies

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Ontology Search

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Expand Search with Wikipedia Topic

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Keyword Extraction & Ranked Ontologies

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OntoSelect Statistics - Multilinguality

English German French Spanish

Portugese Hungarian Italian Polish

Dutch Russian Japanese

Distribution of languages in 136 ontologies with multilingual labels - out of 1530 ontologies currently collected (~9%)

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OntoSelect Statistics - Labels

Most frequently used labels (‘words’, ‘terms’) in 1530 ontologies

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SWSE: Semantic Web Search Engine

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SWSE Architecture

Distributed shared-nothing architecture Implementation scales to billions of triples

Crawler Reasoner Indexer

HTTPQuery

Processor

Ranker

User Interface

Linked Data Raw

Data

Material-isedData

CompleteIndex

Ranks

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OntoSelect-SWSE

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OntoSelect-SWSE Experiments

Experiment Onto Seed set from Google & Yahoo (*.owl, *.daml, *.rdfs) 27,519 data sources (ontologies) 6.5m statements

Experiment Web Crawling six degrees from seed URI

http://www.w3.org/People/Berners-Lee/card 100,555 data sources (instance data + ontologies) 11.9m statements

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Ranked List of Ontologies - Onto

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Ranked List of Ontologies - Web

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Conclusion

SWSE framework facilitates web data experiments

Taking into account real-world instance usage improves ontology ranking

Web data is noisy (more data providers == more noise)

Ontology registry should include rating facility to “vote out” data sources that do not provide consensus view