Interaction among categorical and continuous variables

The article is devoted to the analysis of interaction between independent variables. The first part of the paper presents analysis of interaction between two categorical variables by means of analysis o variance (ANOVA) and multiple regression (MR), the second part presents analysis of interaction between a categorical and a continuous variable by MR method, the third part presents analysis of interaction between two continuous variables by MR method and analysis of centered variables. Each part is illustrated by the analysis of exemplary data sets with the use of the statistical package SPSS. For simplicity, all analyses were limited to the design with two independent variables. peerReviewed publishedVersion