Post-hoc and multiple comparison test – An overview with SAS and R Statistical Package

Analysis of Variance (ANOVA) is a basic but most important tool in Statistics. The simplest form is one way ANOVA wherein equivalence of treatment means are tested. If the means are not equal then the next step is to check which means are different from each other. Post-Hoc and multiple comparison tests are used to identify which pairs of treatment means differ. This paper starts with the overview of Post-Hoc and Multiple Comparison test and discusses the various Post-hoc multiple comparison tests, its usability, positives and limitations. The paper also provides the Statistical Analysis System (SAS) and R Statistical Package codes to carry out the various Post-hoc and multiple comparison tests