IR-part2

19951997 altavista excite infoseek inktomi lycos onen

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: new weigh*ng factor §༊  Train a machine learning model to predict the class r of a document- query pair Introduc)on to Informa)on Retrieval Sec. 15.4.1 Simple example: Using classifica*on for ad hoc IR §༊  A linear score func*on is then: Score(d, q) = Score(α, ω) = aα + bω + c §༊  And the linear classifier would be: Decide relevant if Score(d, q) > θ §༊  … just like when we were doing text classifica*on Introduc)on to Informa)on Retrieval Sec. 15.4.1 Simple example: Using classifica*on for ad hoc IR cosine score α 0.05 R 0.025 R R N R R 0 2 N R N N R R R R N N 3 R N Decision surface N N N 4 5 Term proximity ω The linear score func*on ranks along this dimension Introduc)on to Informa)on Retrieval Introduc*on to Informa(on Retrieval Using many features to determine relevance Introduc)on to...
View Full Document

Ask a homework question - tutors are online