Assessment of Weight Factor in Genetic Programming Fitness Function for Imbalanced Data Classification

Abstract

AbstractIn real-world data classification, applications often have an imbalanced distribution of data over various classes. This imbalanced distribution imposes intense challenges, and because of this, traditional classification methods are not effective in this case. This problem also influences genetic programming (GP). One approach to resolve this issue is to assign a custom high weight to the classes during training. This custom weight assignment may nullify the impact of higher counts of any classes during the learning phase of the classifier. The GP fitness function may introduce the custom weight assignment for the minority class samples. The fitness function performs an essential role in GP and influences each building block of GP. This research work assesses the impact of weight factors in GP’s fitness function for imbalanced data classification. For this assessment, eight imbalanced classification problems are taken from the UCI repository, and intensive experimentation is done on the different weight factors.KeywordsUnbalanced data classificationGenetic programmingWeight assignmentFitness function