Dr. Prutherow believes that people who are under stress will develop more colds than people who are not under stress. When he randomly selected 10 participants and exposed them to high levels of stress, he found that 9 of the participants developed colds. Based on these results, he concluded that stress causes an increase in colds. What is a fundamental flaw in Dr. Prutherow's study?

Question

Quizplus · Accepted Answer

The fundamental flaw in Dr. Prutherow's study is the absence of a control group for comparison. Without a control group, it is impossible to determine whether the observed increase in colds was caused by stress or some other factor. Therefore, his conclusion about stress causing an increase in colds cannot be considered valid.

Dr Prutherow Believes That People Who Are Under Stress Will