  We investigate the problem of machine learning with mislabeled training data.
We try to make the effects of mislabeled training better understood through
analysis of the basic model and equations that characterize the problem. This
includes results about the ability of the noisy model to make the same
decisions as the clean model and the effects of noise on model performance. In
addition to providing better insights we also are able to show that the Maximum
Likelihood (ML) estimate of the parameters of the noisy model determine those
of the clean model. This property is obtained through the use of the ML
invariance property and leads to an approach to developing a classifier when
training has been mislabeled: namely train the classifier on noisy data and
adjust the decision threshold based on the noise levels and/or class priors. We
show how our approach to mislabeled training works with multi-layered
perceptrons (MLPs).
