http://en.wikipedia.org/wiki/Singular_value_decomposition http://en.wikipedia.org/wiki/Singular_value_decomposition http://www.igvita.com/2007/01/15/svd-recomm

http://en.wikipedia.org/wiki/Singular_value_decomposition http://en.wikipedia.org/wiki/Singular_value_decomposition http://www.igvita.com/2007/01/15/svd-recommendation-system-in-ruby/ http://www.igvita.com/2007/01/15/svd-recommendation-system-i... Should get you started.