... dis-tribution (the “actual” curve), the type of M1 in the battalion, the mean failures per tank in the battalion, and a Poisson distributionapplied using the actual mean number of failures per tank (the “expected” ... largeenough is to split the data into two sets.” The training set is used to estimate the model, and the test set is used to evaluate the predictive ability of the model.84 The Effects of Equipment Age ... used to predict the dependentvariable value associated with the test set observation. The removedobservation is then returned to the dataset, and another observationthen becomes the test set....