At this point, we can only note that we used SVM as the basic underlying classifier in our classification and regression experiments, but we used logistic regression as the basis for our ordinal regression.
we can see in Table 2 that the best results are achieved for regression, where the mean squared error is within half a point away for the 11-way and the 5-way class inventories, and it is about four times lower for the 3-way one.