Factorial ANOVA and ANCOVA

This chapter introduces two complex difference statistics: factorial analysis of variance (ANOVA) and analysis of covariance (ANCOVA). Both factorial ANOVA and ANCOVA indicate whether considering more than one independent variable at a time gives you additional information over and above what you would get if you did the appropriate basic inferential statistics for each independent variable separately. Both of these inferential statistics have two or more independent variables and one scale (normally distributed) dependent variable. This chapter helps the reader understand when to use each of these methods, what assumptions must be met, how to check the assumptions, and how to calculate and interpret these methods using SPSS.