A rum rickhouse intern wants to tune every knob on the same barrel-end photos that will later be called “the test.” Why keep training, validation, and a final untouched split separate?
Select an answer to reveal the explanation.
Short Explanation
Training is practice, validation is a coach’s clipboard, and the final test is the sealed exam booklet. If you tune on that sealed booklet, the last score is no longer honest. Separate jobs keep the final number clean.
Full Explanation
The training partition updates parameters. Validation supports model or hyperparameter selection. A final held-out test set estimates performance only after selection is finished, so tuning decisions do not contaminate that last metric.