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Graph-based Word Sense Disambiguation


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Unsupervised Graph-based
Word Sense Disambiguation
Using Measures of Word
Semantic Similarity

Published in: Technology
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Graph-based Word Sense Disambiguation

  1. 1. Unsupervised Graph-based Word Sense Disambiguation Using Measures of Word Semantic Similarity Tăbăranu Elena-Oana 1
  2. 2. Bibliography ● Ravi Sinha and Rada Mihalcea, Unsupervised Graph-based Word Sense Disambiguation Using Measures of Word Semantic Similarity, In Proceedings of the IEEE International Conference on Semantic Computing (ICSC 2007), Irvine, CA, September 2007 ● Rada Mihalcea, Unsupervised Large-Vocabulary Word Sense Disambiguation with Graph-based Algorithms for Sequence Data Labeling, In Proceedings of the Joint Conference on Human Language Technology / Empirical Methods in Natural Language Processing (HLT/EMNLP), Vancouver, October, 2005 Tăbăranu Elena-Oana 2
  3. 3. Plan 1. Introduction 2. Graph-based Centrality for WSD 3. Measures of Semantic Similarity 4. Graph-based Centrality Algorithms 5. Demo Tăbăranu Elena-Oana 3
  4. 4. 1. Introduction ● WSD = assign automatically the most appropriate meaning to a polysemous word within a given context ● Example: 1. The plant is producing far too little to sustain its operation for more than a year. (fabrică) 2. An overabundance of oxygen was produced by the plant in the third week of the study. (plantă) Tăbăranu Elena-Oana 4
  5. 5. 2. Graph-based Centrality for WSD(I) ● GWSD = graph representation used to model word sense dependencies in text (WSD with graphs, not just word window) ● Goal: identify the most probable sense (label) for each word Tăbăranu Elena-Oana 5
  6. 6. 2. Graph-based Centrality for WSD(II) Tăbăranu Elena-Oana 6
  7. 7. Example The church bells no longer rung on Sundays. ● church 1: one of the groups of Christians who have their own beliefs and forms of worship 2: a place for public (especially Christian) worship 3: a service conducted in a church ● bell 1: a hollow device made of metal that makes a ringing sound when struck 2: a push button at an outer door that gives a ringing or buzzing signal when pushed 3: the sound of a bell ● ring 1: make a ringing sound 2: ring or echo with sound 3: make (bells) ring, often for the purposes of musical edification ● Sunday 1: first day of the week; observed as a day of rest and worship by most Christians Tăbăranu Elena-Oana 7
  8. 8. 3.Measures of Semantic Similarity ● Quantify the degree to which two words are semantically related using information drawn from semantic networks ● Word similarity measures 1. Leacock & Chodorow 2. Leck 3. Wu and Palmer 4. Resnik 5. Lin 6. Jiang & Conrath ● Tăbăranu Elena-Oana 8
  9. 9. 4.Graph-based Centrality Algorithms ● Indegree ● Closeness ● Betweenness ● Page Rank Tăbăranu Elena-Oana 9
  10. 10. 5. Demo - GWSD Dependencies ● ● WordNet (semantic hierarchy) ● WordNet::QueryData ● WordNet::Similarity(implementation of similarity measures) Input ● ● Senseval-2, Senseval-3 datasets in Semcor format GWSD improvements ● ● Combine similarity measures(jcn for nouns, lch for verbs, lesk for other parts of speech) ● Voting system between 4 centrality algorithms Tăbăranu Elena-Oana 10