In a matrix representing the structure of a factorial design, the mean differences between the rows define the interaction between the factors.

Question

Quizplus · Accepted Answer

The mean differences between the rows (or columns) in a matrix representing the structure of a factorial design define the main effects of the factors, not the interaction between the factors. Interaction effects are identified by the non-additivity of the effects of the factors when combined, not simply by differences between row or column means.

In a Matrix Representing the Structure of a Factorial Design