What does K-fold cross-validation assess?

K-fold cross-validation is a technique used primarily to assess the generalization ability of a predictive model. By dividing the dataset into K subsets or "folds," this method allows for a more reliable estimate of model performance on unseen data.

During the process, the model is trained on K-1 of the folds and validated on the remaining fold. This is repeated K times, with each fold serving as the validation set once. The overall performance is then averaged to provide a single estimate of the model's accuracy. This technique helps to ensure that the model is not just memorizing the training data but is capable of making accurate predictions on new data, which is a crucial aspect of building effective and robust machine learning models.

In contrast, the other options do not relate specifically to K-fold cross-validation. Visual data representations focus on data presentation rather than model validation. Storage efficiency pertains to how data is organized and stored, not how well a model performs. Clustering efficacy concerns how well a model groups data points together, which is distinct from assessing a predictive model's generalization ability.