Hostility measure for multi-level study of data complexity
Complexity measures aim to characterize the underlying complexity of supervised data. These measures tackle factors hindering the performance of Machine Learning (ML) classifiers like overlap, density, linearity, etc. The state-of-the-art has mainly focused on the dataset perspective of complexity, i.e., offering an estimation of the complexity of the whole dataset. Recently, the instance perspective has also been addressed. In this paper, the hostility measure, a complexity measure offering a multi-level (instance, class, and dataset) perspective of data complexity is proposed. The proposal is built by estimating the novel notion of hostility: the difficulty of correctly classifying a point, a class, or a whole dataset given their corresponding neighborhoods. The proposed measure is estimated at the instance level by applying the k-means algorithm in a recursive and hierarchical way, which allows to analyze how points from different classes are naturally grouped together across partitions. The instance information is aggregated to provide complexity knowledge at the class and the dataset levels. The validity of the proposal is evaluated through a variety of experiments dealing with the three perspectives and the corresponding comparative with the state-of-the-art measures. Throughout the experiments, the hostility measure has shown promising results and to be competitive, stable, and robust.
This research has been supported by grants from Rey Juan Carlos University (Ref: C1PREDOC2020), Madrid Autonomous Community (Ref: IND2019/TIC-17194) and the Spanish Ministry of Science and Innovation, under the Retos-Investigación program: MODAS-IN (Ref: RTI-2018-094269-B-I00). We would like to thank Antonio Alonso Ayuso and Emilio López Cano from the Data Science Laboratory at Rey Juan Carlos University for the checking of mathematics. Funding Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Author information
- Artículos de Revista