A study attempts to compare two sunscreens. Each of 50 subjects with varying skin complexions will use both sunscreens-Screen A on one side of the body and Screen B on the other side. For each subject, a coin is tossed to determine which side receives Screen A and which receives Screen B. Researchers measure the amount of ultraviolet light exposure over both treated areas for each subject. This is an example of:
A)a matched pairs experiment.
B)a double-blind observational study.
C)a stratified analysis.
D)the placebo effect.

Question

Quizplus · Accepted Answer

This is a matched pairs experiment because each subject serves as their own control, with one side of the body receiving one type of sunscreen and the other side receiving the other type. The random assignment of which side receives which sunscreen helps to control for individual differences between subjects.

A Study Attempts to Compare Two Sunscreens