I refer you to Breiman's paper Statistical Modeling - A Tale of Two Cultures where he illustrated some examples of descriptive modelling. Under section 11.1, 100 runs of regression were performed, each time leaving randomly selected 10% of the data. May I know what is the purpose of performing 100 runs and getting the average error rate and relationship between the outcome and explanatory?
I understand the objective of creating tests sets in predictive modelling is as to prevent overestimating the predictive accuracy of the model. But I do not quite understand in the context of descriptive modelling.