Use the Guidelines to Evaluate the Study

Multiple Choice

Use the guidelines to evaluate the study. From the information given, what is the biggest flaw in the study?
-A medical researcher randomly selects 500 Japanese people and 500 Americans. She questions the 1000 people. She finds that the Americans work longer hours on average and also that the
Americans have a higher rate of heart disease. She concludes that working longer hours is
Associated with a higher incidence of heart disease.

A) Variables are hard to define/measure
B) Selection bias
C) The source
D) Participation bias
E) Confounding variables