For this report about statistical studies, identify Any potential sources of bias you can detect and any problems you see in generalizing to the population of interest (if possible). If you can't tell, then say so-this often happens when we read about a survey.

In order to determine how adults of legal drinking age in their city feel about whether drinking and driving was a problem, researchers waited outside a bar they had randomly selected from a list of such establishments. They rolled a ten-sided die and it came up 4, so they stopped the fourth person who came out of the bar, then every 10th person after that, and asked whether he or she thought drinking and driving was a serious problem.