A physical education researcher wishes to determine if walking every day affects the health of middle-aged men. The researcher randomly identifies 400 participants in two groups. Members of one group belong to a health club and walk on its track and members of the other do not. After two months, the researcher decides the group who walks daily is healthier and concludes that walking positively affects men's health. This conclusion is of questionable validity because:
A) of the placebo effect.
B) of confounding variables in the study.
C) the study is not double-blind.
D) the researcher is not a doctor.

Question

Quizplus · Accepted Answer

The presence of confounding variables in the study makes it difficult to establish a cause-and-effect relationship between walking and improved health. Other unspecified factors may have contributed to the observed differences between the two groups. The researcher should have controlled for potential confounding variables or used a randomized controlled trial design with a placebo group to ensure that the observed effects were due to walking and not other factors.

A Physical Education Researcher Wishes to Determine If Walking Every