Ensemble‐ and distance‐based feature ranking for unsupervised learning. Issue 7 (3rd March 2021)

• Record Type: Journal Article
• Authors: Petković, Matej; Kocev, Dragi; Škrlj, Blaž; Džeroski, Sašo
• Is Part Of: International journal of intelligent systems. Volume 36:Issue 7(2021)
• Page Start: 3068
• Page End: 3086
• Publication Date: 2021-03-03
• Subjects: extra trees -- feature ranking -- relief -- tree ensembles -- unsupervised learning; Artificial intelligence -- Periodicals; Expert systems (Computer science) -- Periodicals; Intelligence artificielle -- Périodiques; Systèmes experts (Informatique) -- Périodiques; 006.3
• DOI: 10.1002/int.22390
• Languages: English
• ISSNs: 0884-8173

Abstract

Abstract: In this study, we propose two novel (groups of) methods for unsupervised feature ranking and selection. The first group includes feature ranking scores (Genie3 score, RandomForest score) that are computed from ensembles of predictive clustering trees. The second method is URelief, the unsupervised extension of the Relief family of feature ranking algorithms. Using 26 benchmark data sets and 5 baselines, we show that both the Genie3 score (computed from the ensemble of extra trees) and the URelief method outperform the existing methods and that Genie3 performs best overall, in terms of predictive power of the top‐ranked features. Additionally, we analyze the influence of the hyper‐parameters of the proposed methods on their performance and show that for the Genie3 score the highest quality is achieved by the most efficient parameter configuration. Finally, we propose a way of discovering the location of the features in the ranking, which are the most relevant in reality.