This paper reviews the Ferrara-Preti screening model and shows that recent laboratory and pilot plant data validate this approach. The model successfully predicts the partition curve (selectivity function) and therefore the product size distributions, given the feed size distribution. Some improvement in the application of the model, concerning numerical solution of the equations and parameter estimation, are indicated. Information is then given on the influence of some operating conditions on the screen performance studied through the modification of the model parameters, a way that could be useful for a more complete approach to modelling of screening operations. Some applications of the model to improvement of screening operations, sizing of screens, simulation of screening and of integrated plant operations are discussed.