POST HOC analysis in biometrics

In this paper we have conducted comparison of four post-hoc tests (LSD, Bonferroni, Scheffe, Tukey), whom have we used on four data sets. Every one of four biometrics sets contained three groups and every group had equal number of observations. Data sets differed in size (n 30) and in the coefficient of variation ( CV 20%). We have used one-way analysis of variance, calculated by GLM procedure, to perform statistical analysis. Results were further analysed by computer program Statistica v.8.0. (StatSoft, Inc., 2007). Based on results of analysis we have observed that most liberal of all test was LSD test (lowest statistically significant differences between all observations in all data sets). More conservative tests (Bonferroni, Scheffe and Tukey) had higher values of statistically significant differences between all groups of observations (A-B, A-C and B-C). Also, usage of conservative tests in post-hoc can show no statistical significance between observations, what won't be the case if more liberal tests, like LSD test, are used.