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Hui Fang (ACL 2008) presentation 2009/02/04 Rick Liu
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Intro. “Re”-examine? None of the previous studies is able to show significant performance improvement through query expansion using information only from manually created lexical resources. Re-examine the problem of query expansion using lexical resources in recently proposed axiomatic framework.
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Intro. Axiomatic framework? Hui Fang & ChengXiang Zhai proposed. (SIGIR2005) Anatomize existing retrieval functions such as Okapi, Dirichlet Prior, etc. and derive a new retrieval formula.
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Axiomatic Retrieval Model
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Comparison Fang & Zhai SIGIR2006 (Semantic Term Matching in …) Co-occurrence, document frequency, etc. Fang ACL2008(this) Lexical resources
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Lexical Resources WordNet Dependency-based thesaurus.
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Similarity Function WordNet Definition * 1 Relation * 5 Dependency-based thesaurus. Dependency * 1
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WordNet : Definition
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WordNet : Relation Synonym : X and Y are interchangeable Hypernym : Y is a kind of X Hyponym : X is a kind of Y Holonym : Y is a part of X Meronym : X is a part of Y
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Dependency-based Thesaurus
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Combination
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Experiment Design 6 TREC Collections Only stemming with Porter’s stemmer.
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Experiment Design 6 TREC Collections Only stemming with Porter’s stemmer.
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Experiment Design WordNet 3.0 Lemur Toolkit TrecWN library C++ functions as WordNet Interface Evaluation MAP gMAP( geometric ) : emphasizes the performance of difficulty queryies.
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Experiment Results
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Binary POS
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Experiment Results
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Better than relation Smaller coverage
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Experiment Results
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