'Binary independence model' diaporamas de présentation

Chapter 7

Chapter 7. Retrieval Models. Retrieval Models. Provide a mathematical framework for defining the search process Includes explanation of assumptions Basis of many ranking algorithms Progress in retrieval models has corresponded with improvements in effectiveness

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Lecture 2: Retrieval Models

Lecture 2: Retrieval Models. Maya Ramanath. QQ1. Vector space model: 0 for non-presence of a term, 1 for presence: Query: q1 AND q2 AND q3 Compare the set of results returned by the vector space model and boolean model. Term weighting (1/3): tf. Query: Cat. D2. D3. D1. D1. D3.

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Weighting Schemes

Weighting Schemes. Document Representation Tf-Idf scheme Some extensions of Tf-Idf BM-25 BM-25F. Document Representation. tf-idf weighting. Variant tf-idf functions. Variant tf-idf functions. BM-25. BM-25, IDF. Binary Independence Model. BM-25f. BM-25f. Reference.

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