Question

A researcher is studying the effects of three drugs (A, B, and C) on blood cholesterol, in three different age groups. Which of the following is an example of an interaction effect? Drug C lowers blood cholesterol by the greatest amount in all groups, while Drug B has no effect and Drug A minimal effect. Drug B lowers blood cholesterol more than Drug A in the youngest age group, but they have equal effect on the oldest age group. The youngest age group has the greatest difference in blood cholesterol at the start of the study, and the lowest by the end of the study. The oldest age group has the highest blood cholesterol at the start of the study but the lowest blood cholesterol by the end.

Answer 1

Out of the four, the 2nd condition, Drug B lowers blood cholesterol more than drug A in the youngest age group, but they have equal effect on the oldest age group is an example of an interaction effect.

The other three conditions do not have interaction effect.