The limits of the external validity of the effects of each of the two independent variables in a complex design are specified when
A) there is no interaction effect of the two variables and neither variable produces a main effect.
B) there is no interaction effect of the two variables but significant main effects for both variables.
C) there is no interaction effect of the two variables and one independent variable has a main effect but the other variable does not.
D) there is an interaction effect of the two variables and main effects of the variables may or may not be present.

Question

Quizplus · Accepted Answer

When there is an interaction effect of the two independent variables in a complex design, the limits of the external validity of their effects cannot be specified without considering the nature and direction of the interaction. Additionally, main effects may or may not be present, making it difficult to determine the independent effects of each variable on the outcome. Hence, option D is the correct answer.

The Limits of the External Validity of the Effects of Each