  The monotonic ordinal classification has increased the interest of
researchers and practitioners within machine learning community in the last
years. In real applications, the problems with monotonicity constraints are
very frequent. To construct predictive monotone models from those problems,
many classifiers require as input a data set satisfying the monotonicity
relationships among all samples. Changing the class labels of the data set
(relabelling) is useful for this. Relabelling is assumed to be an important
building block for the construction of monotone classifiers and it is proved
that it can improve the predictive performance.
  In this paper, we will address the construction of monotone datasets
considering as noise the cases that do not meet the monotonicity restrictions.
For the first time in the specialized literature, we propose the use of noise
filtering algorithms in a preprocessing stage with a double goal: to increase
both the monotonicity index of the models and the accuracy of the predictions
for different monotonic classifiers. The experiments are performed over 12
datasets coming from classification and regression problems and show that our
scheme improves the prediction capabilities of the monotonic classifiers
instead of being applied to original and relabeled datasets. In addition, we
have included the analysis of noise filtering process in the particular case of
wine quality classification to understand its effect in the predictive models
generated.
