Table 4. The classification accuracies of each piece after applied to OVA in the classification of multi-class EEG signals using the Random Forests classifier with and without ADASYN using 5-FCV (the third and fourth approaches).

The obtained piece after OVO	The obtained Classification accuracy (%) Without ADASYN	The obtained Classification accuracy (%) With ADASYN
Class 1-others (the combination of class 2, class 3, class 4, and class 5)	98.10	98.40
Class 2-others (the combination of class 1, class 3, class 4, and class 5)	83.00	97.70
Class 3-others (the combination of class 1, class 2, class 4, and class 5)	84.60	88.50
Class 4-others (the combination of class 1, class 2, class 3, and class 5)	91.20	92.70
Class 5-others (the combination of class 1, class 2, class 3, and class 4)	88.10	91.50
The overall accuracy (average score)	89.00	91.72