search for: doubt1

Greetings- Using R 1.5.0 under linux and the latest MASS and nlme, I am trying to develop a three-level (two levels of nesting) model with a dichotomous oucome variable. The unconditional model is thus: > doubt1.pql<-glmmPQL(fixed = r.info.doubt ~ 1, random = ~1 | groupid/participantid, + family = binomial, data = fgdata.10statements.df) iteration 1 iteration 2 iteration 3 iteration 4 iteration 5 > summary(doubt1.pql) Linear mixed-effects model fit by maximum likelihood Data: fgdata.10statement...

...s tutorial on Learning to Rank. I have discussed a few things with him(over mail) about feature extraction for LTR algorithms. Over the last week I have been following the mailing list discussions here and researching a bit about the issues myself. I wanted to discuss about a few issues/thoughts: *Doubt1:* *Feature Extraction/Selection:* The various datasets listed on MSR's LETOR have a limited set of features. Current implementation in xapian's LETOR has 5 features[tf,idf,doc_len,coll_tf,coll_len]. While algorithms for learning ranking models have been intensively studied, this is not the...