AI GLOSSARY · DATA & ML
Overfitting
When a model memorises training data and performs poorly on new data.
Example
Perfect training accuracy but poor test accuracy.
Learn it by doing
Reading a definition is a start; using the idea makes it stick.
Related terms
DATA & MLBaselineA simple reference result that a model must beat to be worth using.DATA & MLTrain/test splitKeeping some data aside, unseen during training, to measure real performance.DATA & MLData leakageWhen information from the test set or the future sneaks into training, making results look better than they are.DATA & MLClassificationPredicting a category, such as spam or not spam.DATA & MLRegressionPredicting a number, such as a price or a quantity.DATA & MLClusteringGrouping similar items without predefined labels.