Joseph wanted to know the drug habits of his senior high school class. He sent out surveys to 300 of his fellow students. He got 130 surveys back, all claiming significant drug use. Why should Joseph be careful about concluding that drug use is rampant on his campus?

Question

Quizplus · Accepted Answer

Joseph should be careful about concluding that drug use is rampant on his campus because of volunteer bias. The 130 surveys that he received back represent only a small portion of the total population and only those who were willing to participate in the survey. Those who are more likely to use drugs may have been more motivated to respond, leading to an overestimation of drug use on campus.

Joseph Wanted to Know the Drug Habits of His Senior