Voting-based ensemble learning for partial lexicographic preference forests over combinatorial domains

• Published in: Annals of mathematics and artificial intelligence Vol. 87; no. 1-2; pp. 137 - 155
• Main Authors: Liu, Xudong, Truszczynski, Miroslaw
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.10.2019; Springer; Springer Nature B.V
• Subjects: Accuracy; Analysis; Artificial Intelligence; Cognition & reasoning; Combinatorial analysis; Complex Systems; Computer Science; Decision making; Decision theory; Decision trees; Ensemble learning; Forests and forestry; Majority rule; Mathematics; Optimization; Preferences; Voting; Voting theory; Maximum satisfiability; Preference modeling and reasoning; Preference learning; Computational complexity theory; 68T30; Lexicographic preference models; Social choice theory
• ISSN: 1012-2443; 1573-7470
• DOI: 10.1007/s10472-019-09645-7

We study preference representation models based on partial lexicographic preference trees (PLP-trees). We propose to represent preference relations as forests of small PLP-trees (PLP-forests), and to use voting rules to aggregate orders represented by the individual trees into a single order to be taken as a model of the agent’s preference relation. We show that when learned from examples, PLP-forests have better accuracy than single PLP-trees. We also show that the choice of a voting rule does not have a major effect on the aggregated order, thus rendering the problem of selecting the “right” rule less critical. Next, for the proposed PLP-forest preference models, we develop methods to compute optimal and near-optimal outcomes, the tasks that appear difficult for some other common preference models. Lastly, we compare our models with those based on decision trees, which brings up questions for future research.