An observational study was done to assess the effects of environmental infl uences on drinking by college students in a university-sponsored pub. Eighty-two students over the age of 21 were observed. The observers used a checklist to record whether the participant was male or female and whether the participant was with one other person or was in a group of two or more other people. Each observation session was always from 3 P.M. to 1 A.M ., and observations were made Monday through Saturday. The observations were made over a 3-month period. Two observers were always present during any observation session. Each participant was observed for up to 1 hour from the time he or she ordered the fi rst beer. The data were summarized in terms of the number of beers drunk per hour. The results showed that men drank more and men drank faster than did women. Men drank faster when with other men, and women also drank faster with men present. Both men and women drank more in groups than when with one other person. These results indicate that the environment within which drinking occurs plays an important role in the nature and extent of that drinking.

A. Identify the observational method being used in this study, and explain why you decided on the observational method you chose.

B. Identify the independent and dependent variables in this study, and describe the operational definition of each level of the independent variable.

C. How could the researchers control for reactivity in this study? What ethical concerns might arise from their approach?

D. Identify one aspect of the procedures in this study that would likely increase the reliability of the observations.

E. Identify one aspect of the procedures in this study that would likely limit the external validity of the findings of this study.