Generalizable Singular Value Decomposition for Ill-posed Datasets
Kjems, Ulrik, Hansen, Lars Kai, Strother, Stephen C.
–Neural Information Processing Systems
So which of the two variances is "correct"? From a modelling point of view, the variance from the test example tells us the true story, so the training set variance should be regarded as biased.
Neural Information Processing Systems
Dec-31-2001