In predictive modeling, which concept involves holding out part of the data for empirical validation?

The concept that involves holding out part of the data for empirical validation is cross-validation. This technique is crucial in predictive modeling as it helps to assess how the results of a statistical analysis will generalize to an independent data set. By partitioning the original dataset into a training set and a test (or validation) set, cross-validation allows for the model to be trained on one subset of the data and validated on another, thereby reducing the risk of overfitting and providing a more reliable measure of the model's performance.

During cross-validation, the model's accuracy can be evaluated using the validation set, which represents unseen data. This is vital because it provides insights into how well the model functions in practice rather than just fitting to the training data.

Data preparation, data analysis, and model fitting are all critical steps in the predictive modeling process but do not specifically denote the method of holding out data for validating the model's predictive power. Data preparation involves cleaning and organizing data, data analysis focuses on interpreting data to extract insights, and model fitting refers to the technique of training the model using the prepared data. None of these steps explicitly refer to the concept of partitioning data for validation as cross-validation does.