“…Still, to calculate the estimated sample size needed for a hypothesis test, Neyman-Pearson is used, and to assess the validity of the hypothesis, P designed by Fish. Many studies does not even bother to calculate the sample size required for adequate statistical power [8,9], and few researchers remember to calculate the power of the sample after the final survey, the little-known observed power. Result: It is estimated that about 90% of published trials have insufficient sample, where such data are available [10].…”