AI Glossary
Overfitting
What is Overfitting?
When an AI model learns training data too well — including its noise and errors — resulting in poor performance on new, unseen data. A fundamental machine learning problem addressed through techniques like regularisation, dropout, and more diverse training datasets.
Example in practice
A data scientist who trains a churn prediction model on last year's customer data and finds it performs poorly on this year's customers has likely built an overfit model — it memorised patterns that no longer hold.