in the pagehttps://issues.apache.org/jira/browse/MAHOUT-420
Prediction(u,i) = sum(all n from N: similarity(i,n) * rating(u,n)) / sum(all n from N: abs(similarity(i,n))) why must devide sum(all n from N: abs(similarity(i,n))), if similarity(i,n) is quite small , i don`t want redommend that item,i only want recommend very similary item. it seems that not work very well.
