Old and New Cross Sections

New cross section calculations are usually advertised as improvements over previous ones. Nevertheless these claims are not always supported by rigorous statistical tests. A set of electron impact ionization cross sections for inner shells, suitable for Monte Carlo particle transport, has been evaluated in a large scale validation test with respect to an extensive collection of experimental data retrieved from the literature. It includes the cross sections tabulated in EEDL (Evaluated Electron Data Library), recent calculations by Bote and Salvat, the Binary-Encounter-Bethe (BEB) model and the Deutsch-Mrk (DM) model. The cross sections were compared to experimental data by means of goodness-of-fit tests. The picture that emerges from the validation test does not fully support the expectations of improvement. The complete and final results of the validation process are reported in detail and critically discussed.