G*Power 3 is a major extension of, and improvement over, G*Power 2 . It covers statistical power analyses for many different statistical tests like:F test,t test,2-test and z test familiessome exact tests. G*Power is offering five different types of statistical power analysis:A priori (sample size N is computed as a function of power level 1-???, significance level ???, and the to-be-detected population effect size)Compromise (both ??? and 1-??? are computed as functions of effect size, N, and an error probability ratio q = ???/???)Criterion (??? and the associated decision criterion are computed as a function of 1-???, the effect size, and N)Post-hoc (1-??? is computed as a function of ???, the population effect size, and N)Sensitivity (population effect size is computed as a function of ???, 1-???, and N)G*Power 3 provides improved effect size calculators and graphic options. It supports both a distribution-based and a design-based input mode.What\'s New in This Release: [ read full changelog ]· Fixed a problem in the X-Y plot for a range of values for Generic F tests. The degrees of freedom were not properly set in the graph, leading to erroneous plot values.