Book Image

Machine Learning for Imbalanced Data

By : Kumar Abhishek, Dr. Mounir Abdelaziz
Book Image

Machine Learning for Imbalanced Data

By: Kumar Abhishek, Dr. Mounir Abdelaziz

Overview of this book

As machine learning practitioners, we often encounter imbalanced datasets in which one class has considerably fewer instances than the other. Many machine learning algorithms assume an equilibrium between majority and minority classes, leading to suboptimal performance on imbalanced data. This comprehensive guide helps you address this class imbalance to significantly improve model performance. Machine Learning for Imbalanced Data begins by introducing you to the challenges posed by imbalanced datasets and the importance of addressing these issues. It then guides you through techniques that enhance the performance of classical machine learning models when using imbalanced data, including various sampling and cost-sensitive learning methods. As you progress, you’ll delve into similar and more advanced techniques for deep learning models, employing PyTorch as the primary framework. Throughout the book, hands-on examples will provide working and reproducible code that’ll demonstrate the practical implementation of each technique. By the end of this book, you’ll be adept at identifying and addressing class imbalances and confidently applying various techniques, including sampling, cost-sensitive techniques, and threshold adjustment, while using traditional machine learning or deep learning models.
Table of Contents (15 chapters)

Multi-label classification

Multi-label classification is a classification task where each instance can be assigned to multiple classes or labels simultaneously. In other words, an instance can belong to more than one category or have multiple attributes. For example, a movie can belong to multiple genres, such as action, comedy, and romance. Similarly, an image can have multiple objects in it (Figure 6.14):

Figure 6.14 – Multi-label image classification with prediction probabilities shown

But how is it different from multi-class classification? Multi-class classification is a classification task where each instance can be assigned to only one class or label. In this case, the classes or categories are mutually exclusive, meaning an instance can belong to just one category. For example, a handwritten digit recognition task would be multi-class since each digit can belong to only one class (0-9).

In summary, the main difference between multi-label...