What statistical method evaluates how well a model generalizes by partitioning data into subsets?

The method that effectively evaluates how well a model generalizes by partitioning data into subsets is cross-validation. This technique involves dividing the dataset into separate subsets, typically referred to as "folds." The model is then trained on a subset of the data and tested on a different subset to assess its performance. This process is repeated multiple times, each time using different partitions of the data, which allows for a comprehensive evaluation of the model's performance across various segments of the dataset.

Cross-validation helps in understanding how the model's predictive performance will vary with different data subsets, ensuring that the model is not merely fitting to the particular training data but can perform well on unseen data. This is crucial in building robust models that generalize beyond the training set, ultimately leading to better outcomes in real-world applications.

In contrast, the other methods serve different purposes. Data augmentation is used to artificially expand the training dataset through transformations. Feature selection focuses on identifying the most relevant features for improving model performance. Hyperparameter tuning involves optimizing the parameters of the model to enhance its performance but does not directly evaluate generalization through data partitioning as cross-validation does.