Hi, I am using the superpc package. By superpc.train (data, type="regression") I calculated the standardized regression coefficients for measuring the univariate effect of each feature on a continuous response y. By superpc.cv(compute.fullcv=TRUE, compute.preval=FALSE, n.components=3, n.fold=10) I used cross validation to estimate the optimal feature threshold and choose only those features whose univariate coefficient exceeds the threshold. To choose the best threshold I plotted the cross-validation curves by superpc.plotcv(cv.type="full'). I work with 55 features and 43 samples. I noticed that by repeating the call of superpc.cv (with the same argument values) and then plotting the curves by superpc.plotcv, the curves change and sometimes the best threshold changes value. Please note that I chose compute.fullcv =TRUE, therefore full cross-validation is done. Moreover, if n.fold=10 the result is not significant for any threshold value (the three curves are under the three horizontal lines -likelihood ratio test). However with n.fold<10 there are significant results. I tested also the example provided by the user manual for the explanation of the superpc.plotcv routine. In this case, by repeating the call of superpc.cv (with the same argument values) the three curves change, but they always remain under the three horizontal lines. So it seems that the result is always not significant (likelihood ratio). Is my interpretation of the likelihood ratio test correct? As the curves change, has someone any explanation or solution for the correct choice of the best threshold value? I also noticed that by following the instructions of the superpc tutorial (http://www-stat.stanford.edu/~tibs/superpc/tutorial.html) the obtained cv.plot is not similar to the one provided in the tutorial as pdf version. I use R 2.2.1 version. Is it possible that the rnorm() function (seed=4648) did not generate the same set of numbers as that used by R. Tibshirani? Thank You in advance Rossana ----------------------------------------------- Rossana Dell'Anna, PhD ITC-irst Centre for Scientific and Technological Research Via Sommarive, 18 - 38050 Trento, ITALY ph: +39 0461 314 486 e-mail: dellanna at itc.it