Sixty-four male students were ordered, after they had violated university alcohol rules, to meet with a school counselor. Borsari and Carey (2005) randomly assigned these students to one of two conditions. Those in the first condition were assigned to undergo a newly developed brief motivational interview (BMI), an intervention in which educational material relates to the students’ own experiences; those in the second condition were assigned to attend a standard alcohol education session (AE) in which educational material is presented with no link to students’ experiences. Based on inferential statistics, the researchers concluded that those in the BMI group had fewer alcohol-related problems at follow-up, on average, than did those in the AE group. 

a. What is the population of interest, and what is the sample in this study? 

b. Was random selection likely used? Explain your answer. 

c. Was random assignment likely used? Explain your answer. 

d. What is the independent variable and what are its levels? What is the dependent variable? 

e. What is the null hypothesis and what is the research hypothesis? 

f. What decision did the researchers make? (Respond using the language of inferential statistics.) 

g. If the researchers were incorrect in their decision, what kind of error did they make? Explain your answer. What are the consequences of this type of error, both in general and in this situation?