What does the term ‘data leakage’ mean in a machine learning context?

Question

Data Science with Python — Medium

What does the term ‘data leakage’ mean in a machine learning context?

Accepted Answer

Data leakage in a machine learning context refers to when information from the test set or future data influences the training process, leading to overly optimistic performance estimates that do not generalize. This can result in models that perform well on training data but fail in real-world scenarios.