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Implementation of Vector Space Model. March 27, 2006. How TA Can Be Used in Vector Space Model?. Let consider a query with keyword microsoft and corporation, q = (microsoft, corporation) Create table for each keyword, e.g., These lists are called “Inverted Lists”. docid.
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Implementation of Vector Space Model March 27, 2006
How TA Can Be Used in Vector Space Model? • Let consider a query with keyword microsoft and corporation, q = (microsoft, corporation) • Create table for each keyword, e.g., • These lists are called “Inverted Lists” docid Tfmicosoft * Idfmicrosoft docid Tfcorporation * Idfcorporation 374 289 43.2 42.1 175 456 23.5 20.1 - Space occupied = O(# of non-zero entries in the matrix) - So its not cheap in terms of space
How TA Can Be Used in Vector Space Model? • Inverted List • In original database words are generated for given documents • In Inverted List, documents are generated for given words; that’s why this is called Inverted List
How TA Can Be Used in Vector Space Model? • Inverted List • Union of Listmicrosoft and Listcorporation • Keep list sorted by document id • Intersection of Listmicrosoft and Listcorporation • Arrange keywords from more specific to the least