Fig. 1

Nested tenfold cross-validation (CV) procedure for model development and evaluation. In the outer CV loop (on top left), the dataset was partitioned into the ‘Model Development Set’ and ‘Test Set’. In the inner CV loop (on top right), the ‘Model Development Set’ was further partitioned into the ‘Training Set’ and ‘Validation Set’. The inner loop was composed of tenfold cross-validation Grid Search with the aim of obtaining the best parameters for each of the three classifiers assembled. On the bottom of figure, the procedure for one single iteration of the outer CV loop is graphed in diagram form