2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4143The determination of a steeply falling energy spectrum from rare events with non-gaussian measurement errors is a delicate matter. The final shape of the spectrum may be severely distorted as a consequence of non-gaussian tails in the energy resolution of the experiment. We illustrate this effect with the recent experimental efforts to determine the ultra-high energy extreme of the cosmic ray spectrum.11 pages, 5 figuresAstrophysicsHigh Energy Physics - PhenomenologyData Analysis, Statistics and Probabilitytext