Hi, > OK. Does one specify the model with the -m flag in addition to the -intref > option? In essence, what is correct the command line format when using > -intref? -intref ${FSLDIR}/data/first/models_317_bin/L_Thal_bin.bmv -m ${FSLDIR}/data/first/models_317_bin/intref_thal/L_Hipp_bin.bmv > What do you mean by "leave-one-out cross-validation " leave-one-out cross-validation is a fairly standard technique for assessing accuracy in an nearly unbiased manner (particularly when sample sizes are not large). The model is trained from all subjects but one, then applied to the left out subject. This is then repeated for each subject. By doing this, the test subject is never included in the training data. Cheers, Brian