Abstract
We analyse and compare the positive and negative arguments on whether quantum interference violates the classical law of the addition of probabilities. The analysis takes into account the results of recent interference experiments in neutron, electron and atom optics. Nonclassical behaviour of atoms was found in atomic experiments where the measurements included their time of arrival and space distribution. We determine probabilities of elementary events associated with the nonclassical behaviour of particles in interferometers. We show that the emergence of the interference pattern in the process of accumulation of such elementary events is consistent with the classical law of the addition of probabilities.