Multiplicity distributions in hadronic and heavy ion reactions

It is shown that the study of multiplicity distributionsP(n) can provide valuable information about the reaction mechanism of strong interactions. The relation betweenP(n) and Bose-Einstein correlations is discussed and the recent Na³⁵ results are interpreted as possible evidence for the existence of a chaotic and a coherent component inP(n). An experiment to test the coherent nature of pion beams is proposed.