▲ 5 r/MLQuestions
Why is my CV R² low despite having a good test R²?
My dataset is relatively small (233 samples) and highly nonlinear (concrete strength). I have tried both 5-fold and 10-fold cross-validation, along with an 80:20 train–test split. While the test R² appears reasonable, the cross-validation R² is quite low. What can I do to improve this?
u/Efficient_Book8373 — 14 hours ago