REPLI: a program in BASIC for determination of approximate sample size

Abstract

REPLI, a program written in elementary BASIC, calculates the approximate sample size, which is required to detect a desired difference between any two group means in an experiment with n groups for a given probability and at three significance levels of the means difference. A prior knowledge of the variability of data in the groups is expected in order to base the estimate on a rational footing. If this knowledge does not exist, an educated guess and/or several trials with different assumptions on the most likely variability can be used. The a priori estimate prevents that sample sizes are completely out of a reasonable range. Since the program is applicable for experimental settings where several groups need be investigated, it is particularly interesting to users of ANOVA and/or comparable non-parametric tests.