Exploring Symmetry of Binary Classification Performance Metrics

Selecting the proper performance metric constitutes a key issue for most classification problems in the field of machine learning. Although the specialized literature has addressed several topics regarding these metrics, their symmetries have yet to be systematically studied. This research focuses o...

Descripción completa

Detalles Bibliográficos
Autores: Luque Sendra, Amalia, Carrasco Muñoz, Alejandro, Martín-Gómez, Alejandro Manuel, Lama-Ruiz, Juan Ramón, Aguayo-González, Francisco (Coordinador), León de Mora, Carlos (Coordinador)
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/82577
Acceso en línea:https://hdl.handle.net/11441/82577
https://doi.org/10.3390/sym11010047
Access Level:acceso abierto
Palabra clave:Performance metrics
Classification
Computational symmetry
Machine learning
Descripción
Sumario:Selecting the proper performance metric constitutes a key issue for most classification problems in the field of machine learning. Although the specialized literature has addressed several topics regarding these metrics, their symmetries have yet to be systematically studied. This research focuses on ten metrics based on a binary confusion matrix and their symmetric behaviour is formally defined under all types of transformations. Through simulated experiments, which cover the full range of datasets and classification results, the symmetric behaviour of these metrics is explored by exposing them to hundreds of simple or combined symmetric transformations. Cross-symmetries among the metrics and statistical symmetries are also explored. The results obtained show that, in all cases, three and only three types of symmetries arise: labelling inversion (between positive and negative classes); scoring inversion (concerning good and bad classifiers); and the combination of these two inversions. Additionally, certain metrics have been shown to be independent of the imbalance in the dataset and two cross-symmetries have been identified. The results regarding their symmetries reveal a deeper insight into the behaviour of various performance metrics and offer an indicator to properly interpret their values and a guide for their selection for certain specific applications.