Analysis of variance (ANOVA) is one of the most frequently used statistical methods in medical research. The need for ANOVA arises from the error of alpha level inflation, which increases Type 1 error probability (false positive) and is caused by multiple comparisons. ANOVA uses the statistic F, which is the ratio of between and within group variances. The main interest of analysis is focused o...

Eta squared is a popular effect size, but contains positive bias. Bootstrapping can be used to remove the bias from eta squared. Compared epsilon and omega squared, bootstrap correction does not make distributional assumption, it easy implement. A real example computer simulations are included illustrate its application. The bias-corrected shows very...

Consider a one-way or two-way ANOVA design. Typically, groups are compared based on some measure of location. The paper suggests alternative methods where measures location replaced by robust effect size that is in part dispersion. used here does not assume the have common That is, it deals with heteroscedasticity. It fairly evident no single method ...