twowaytests: An R package for two-way tests in independent groups designs

Abstract

Two-way tests in independent groups designs are the most frequently used statistical techniques in various fields. In this paper, we present twowaytests package to investigate the effects of two treatments and the associated interaction on the dependent variable. The package offers two-way tests involving two-way ANOVA, parametric bootstrap based generalized test, generalized pivotal quantity based generalized test, two-way ANOVA for trimmed means, two-way ANOVA using M-estimators for location, and two-way ANOVA for medians. The package provides some basic descriptive statistics, pairwise comparisons, variance homogeneity and normality tests, and well-arranged graphical approaches. Furthermore, its web application is freely available at http://www.softmed.hacettepe.edu.tr/twowaytests.

Keywords

• Two-way ANOVA
• Generalized tests
• Two-factor designs