ABSTRACT
Analysis of variance (ANOVA) and Analysis of covariance (ANCOVA) is an abundance of research on incorrect statistical reasoning, indicating that statistical ideas are often misunderstood and misused by students and professionals alike. The primary purpose of an ANCOVA is to reduce within-group variability. Pairwise Multiple Comparisons methods are used to investigate differences between pairs of group means. If the ANOVA F is significant in the first of this two-stage approach to the data analysis, this result is often interpreted to mean that at least one pairwise comparison will show up as significant in the second, post hoc stage of the analysis. The last portion of the assignment will help you gain a better understanding of why the interaction sum of squares turns out as it does in any two-way ANOVA. ANCOVA can achieve this objective even if comparison groups have similar, or even identical, means on the covariate variable.
