1. ABC Inc., located in New York City, specializes in jury selection and providing advice to attorneys. In preparation for the defense of a man indicted for murder in a well-publicized jury-trial in Dallas, Texas, the defense team hired ABC. ABC sent out an intern to Central Park in Manhattan one Sunday morning to find 5 volunteers for a focus group to discuss the case. The intern approached five elderly men who had just finished having breakfast together, and they agreed to participate. ABC presented the facts of the case to the gentlemen and asked what they thought. ABC then wrote up the report and sent it to Dallas. ABC was fired immediately. List five things ABC did wrong and explain why you think they were wrong (from a statistical perspective).

2. A large observational study used records from Canada's national health care system to compare the effectiveness of two ways to treat prostate disease. The two treatments are traditional surgery and a new method that does not require surgery. The records describe many patients whose doctors had chosen one or the other method. The study found that the patients treated by the new method were significantly more likely to die within 8 years. Further study of the data showed that this conclusion was wrong. What is the major flaw in this study?

3. What is the best way to answer each of the questions below: an experiment, a sample survey, or an observational study that is not a sample survey? Explain your choices.

a) Are people generally satisfied with how things are going in the country right now?

b) Do college students learn basic accounting better in a classroom or using an online course?

c) How long do your instructors wait on the average after they ask their class a question?

4. The requirement that human subjects give their informed consent to participate in an experiment can greatly reduce the number of available subjects. For example, a study of new teaching methods asks the consent of parents for their children to be taught by either a new method or the standard method. Many parents do not return the forms so their children must continue to follow the standard curriculum. Why is it not correct to consider these children as part of the control group along with the children who are randomly assigned to the standard method?