Beginner · Data
Imbalanced dataset
Visual diagram · (in preparation) · Math · (in preparation) · Worked example · 3 difficulty levels.
TL;DR. A dataset where the classes are not represented equally, posing challenges for model training.
Technical Definition
A dataset where the classes are not represented equally, posing challenges for model training.
How it works
An imbalanced dataset is one where the number of examples in different classes varies significantly. For instance, in fraud detection, fraudulent transactions (the minority class) are far fewer than legitimate ones (the majority class). This imbalance can cause models to become biased towards the majority class, performing poorly on the minority class, which is often of greater interest.
Related Concepts
- Classification — A supervised learning task where the model assigns inputs to discrete categories.
- Data Preprocessing — Transforming raw data into a format suitable for model training.