Supplementing Interaction: Simple Effects (1 of 3)
The presence of interaction limits the generalizeability of main effects. This is because it is difficult to make a general statement about a variable's effect when the size of the effect depends on the level of a second variable. For example, consider the hypothetical data shown in the figure below. The experiment is on the effect of condition (treatment versus control) on performance for each of two tasks. Since the effect of condition is different for the two tasks, it is not possible to make a general statement about the treatment's effectiveness.
