Validation and overfitting

1. Validation helps us evaluate a quality of the model
2. Validation helps us select the model which will perform best on the unseen data
3. Underfitting refers to not capturing enough patterns in the data

low model's quality on test data, which was unexpected due to validation scores

• https://www.coursera.org/learn/competitive-data-science/lecture/wwGFq/validation-and-overfitting