validation

The initial evaluation of a model's quality. Validation checks the quality of a model's predictions against the validation set. Because the validation set differs from the training set, validation helps guard against overfitting. You might think of evaluating the model against the validation set as the first round of testing and evaluating the model against the test set as the second round of testing.

Practitioners refer to validation when building, training, or evaluating machine learning systems. It appears in research papers, product documentation, and technical discussions about AI capabilities and limitations.