Type III errors occur as a result of miscommunication and not conducting a hypothesis-driven study. http://www.scalelive.com/type-iii-error.html

Kruskal-Wallis tests are used when the assumption of homogeneity of variance is violated for ANOVA. http://www.scalelive.com/kruskal-wallis-and-homogeneity-of-variance.html

Definitions for several hundred words used in research and statistics with links to webpages for each. http://www.scalelive.com/research-and-statistics-dictionary.html

Compare three or more groups on an ordinal outcome or adjust for violations of statistical assumptions when using ANOVA. http://www.scalelive.com/kruskal-wallis.html

Correlations measure the magnitude and direction of relationships between two variables. http://www.scalelive.com/correlations.html

Test-retest reliability assesses the stability of survey instrument scores across time. http://www.scalelive.com/test-retest-reliability.html

Statistical Power and Large Sample Sizes

Large sample sizes increase statistical power and increase the flexibility of detecting all kinds of effect sizes.