Bayesian reasoning versus conventional statistics in High Energy Physics

Abstract

The intuitive reasoning of physicists in conditions of uncertainty is closer to the Bayesian approach than to the frequentist ideas taught at University and which are considered the reference framework for handling statistical problems. The combination of intuition and conventional statistics allows practitioners to get results which are very close, both in meaning and in numerical value, to those obtainable by Bayesian methods, at least in simple routine applications. There are, however, cases in which ``arbitrary'' probability inversions produce unacceptable or misleading results and in these cases the conscious application of Bayesian reasoning becomes crucial. Starting from these considerations, I will finally comment on the often debated question: ``is there any chance that all physicists will become Bayesian?''