In order to evaluate a model we usually take into account the following measures:
True Positives (T P): number of instances classified as belonging to class A that
truly belong to class A; True Negatives (T N): number of instances classified as not
belonging to class A and that in fact do not belong to class A; False Positives (FP):
number of instances classified as class A but that do not belong to class A; False
Negatives (FN): instances not classified as belonging to class v but that in fact do
belong to class A.