Using k-fold cross-validation to assess model performance
In this section, you will learn about the common cross-validation techniques holdout cross-validation and k-fold cross-validation, which can help us to obtain reliable estimates of the model’s generalization performance, that is, how well the model performs on unseen data.
The holdout method
A classic and popular approach for estimating the generalization performance of machine learning models is the holdout method. Using the holdout method, we split our initial dataset into separate training and test datasets—the former is used for model training, and the latter is used to estimate its generalization performance. However, in typical machine learning applications, we are also interested in tuning and comparing different parameter settings to further improve the performance for making predictions on unseen data. This process is called model selection, with the name referring to a given classification problem...