G*Power performs high-precision statistical power analyses for the
most common statistical tests in behavioral research, that is,
t-tests (independent samples, correlations, and any other t-test),
F-tests (ANOVAS, multiple correlation and regression, and any other F-test), and
Chi2-tests (goodness of fit and contingency tables).
G*Power computes
power values for given sample sizes, effect sizes, and alpha levels (post hoc power analyses),
sample sizes for given effect sizes, alpha levels, and power values (a priori power analyses), and
alpha and beta values for given sample sizes, effect sizes, and beta/alpha ratios (compromise power analyses).
The
program may be used to display graphically the relation between any two
of the relevant variables and it offers the opportunity to compute the
effect size measures from basic parameters defining the alternative
hypothesis.
