Cross-Validation Done Right
Estimate performance you can trust.
One Split Is Risky
A single train-test split can flatter or punish your model by luck. Cross-validation averages many splits for a score you can trust.
The K-Fold Idea
K-fold cross-validation slices your data into k equal parts, then trains on k-1 and tests on the one held out, rotating each time.
All lessons in this course
- Why Accuracy Can Lie
- Precision, Recall, and F1
- Reading the Confusion Matrix
- Cross-Validation Done Right