Question

What is interaction? Provide an example about the design of a study that involves the examination of an interaction effect

Answer 1

Interaction:

Interaction effect occurs when one variable depends on the value of another variable.

Example:

Imagine that we are conducting a taste test to determine which food condiment produces the highest enjoyment. We’ll perform a two-way ANOVA where our dependent variable is Enjoyment. Our two independent variables are Food and Condiment.

Our ANOVA model with the interaction term is:

Satisfaction = Food Condiment Food*Condiment

To keep things simple, we’ll include only two foods (ice cream and hot dogs) and two condiments (chocolate sauce and mustard) in our analysis.

If someone asks you, “Do you prefer ketchup or chocolate sauce on your food?” Undoubtedly, you will respond, “It depends on the type of food!” You cannot answer the question without knowing more information about the other variable in the interaction term.

Here enjoyment depends on the condiment