A researcher conducts a two-factor study to evaluate the effect of a medication for males and for females. If the results of the study show a 10-point main effect for the medication (participants taking the medicine average 10 points lower than those in the no-medication condition) and also show a significant interaction between medication and gender, then what can the researcher conclude about the effect of the medication?
A) The medication lowers scores by around 10 points and the effect is the same for males and females.
B) Although the average effect of the medication is to lower scores by 10 points, the exact effect depends on the gender of the participant.
C) Because there is an interaction, you cannot conclude that the medication has any effect.
D) Additional information is needed to come to a conclusion.

Question

Quizplus · Accepted Answer

The significant interaction between medication and gender indicates that the effect of the medication depends on the gender of the participant. Therefore, the researcher cannot conclude that the effect of the medication is the same for males and females. However, the main effect of the medication is still observed as a 10-point decrease in scores overall.

A Researcher Conducts a Two-Factor Study to Evaluate the Effect