Enhance Top-down method with Meta-Classification for Very Large-scale Hierarchical Classification

Recent large-scale hierarchical classification tasks typically have tens of thousands of classes as well as a large number of samples, for which the dominant solution is the top-down method due to computational complexity. However, the top-down method suffers from accuracy deficiency, that is, its accuracy is generally lower than that of the flat approach of 1-vs-Rest. In this paper, we employ meta-classification technique to enhance the classifying procedure of the top-down method. We analyze the proposed method on the aspect of accuracy, and then test it with two realworld large-scale data sets. Our method both maintains the efficiency of the conventional top-down method and provides competitive classification accuracies.