Which of the following is correct?

Question

a) Whenever interactions are found, there must be main effects

b)Whenever main effects are found there must be at least one interaction 

c)When both interactions and main effects are found, the interactions are interpreted first

d)If there are no main effects, there can be no interactions

Answer 1

C is correct.  Interactions represent the combined effects of factors on the dependent measure. When an

interaction effect is present, the impact of one factor depends on the level of the other factor.  When

interaction effects are present, it means that interpretation of the main effects is incomplete or

misleading.