A cosmetics company wants to market a new suntan lotion. The developers recruit 10 volunteers for their study to test the effectiveness of the new lotion. Each volunteer was given the old lotion on one arm, randomly selected, and the other lotion on the other arm. The volunteer was then asked to expose both arms to the sun. The time was measured until there was visible redness in one arm, which was then shielded from the sun. The experiment ended when the other arm showed signs of redness. Below are the times for both arms for each subject. This study design is called:

Question

A cosmetics company wants to market a new suntan lotion. The developers recruit 10 volunteers for their study to test the effectiveness of the new lotion. Each volunteer was given the old lotion on one arm, randomly selected, and the other lotion on the other arm. The volunteer was then asked to expose both arms to the sun. The time was measured until there was visible redness in one arm, which was then shielded from the sun. The experiment ended when the other arm showed signs of redness. Below are the times for both arms for each subject.  This study design is called:

Quizplus · Accepted Answer

This study design is a matched pairs design, as each volunteer serves as their own control by receiving both the old and new lotion on different arms. The purpose of the experiment is to compare the effectiveness of the two lotions on the same subject. The other answer choices do not accurately describe the study design.

A Cosmetics Company Wants to Market a New Suntan Lotion