Why Do We Need a Validation Set in Addition to Training and Test Sets?

You may already be familiar with training and test sets. This is because you need a separate test set to evaluate your model on unseen data to increase the generalizing capability of the model. We do not test our model on the same data used for training. If we do so, the model will try to memorize data and will not generalize on new unseen data. The validation set is also a part of the original dataset.