Multiple Elimination of Base Classifiers in Ensemble Learning Using Accuracy and Diversity Comparisons

Abstract

When generating ensemble classifiers, selecting the best set of classifiers from the base classifier pool is considered a combinatorial problem and an efficient classifier selection methodology must be utilized. Different researchers have used different strategies such as evolutionary algorithms, genetic algorithms, rule-based algorithms, simulated annealing, and so forth to select the best set of classifiers that can maximize overall ensemble classifier accuracy. In this article, we present a novel classifier selection approach to generate an ensemble classifier. The proposed approach selects classifiers in multiple rounds of elimination. In each round, a classifier is given a chance to be selected to become a part of the ensemble, if it can contribute to the overall ensemble accuracy or diversity; otherwise, it is put back into the pool. Each classifier is given multiple opportunities to participate in rounds of selection and they are discarded only if they have no remaining chances. The process is repeated until no classifier in the pool has any chance left to participate in the round of selection. To test the efficacy of the proposed approach, 13 benchmark datasets from the UCI repository are used and results are compared with single classifier models and existing state-of-the-art ensemble classifier approaches. Statistical significance testing is conducted to further validate the results, and an analysis is provided.