> from a past exam, I have the following question: > > Which type of sample survey would provide the most reliable data on the > frequency of cinema-going of the population?
Is there perhaps a problem with selection bias? > > only one of 1,2,3,4 is "correct": > > 1) A house to house survey in the evening Movie goers might not be home in the evening. > 2) A postal survey based on the electoral list Movie goers might be younger than voters, perhaps even too young to be voters (if one believes the stories that movies are directed at preteens and teens). > 3) Interviewing outside the cinema Not to many non-"movie goers" hang around outside cinemas. But you could find out about the ages of movie goers quite directly. > 4) A household survey based on a population census or register Everybody is in but some might take more follow up to get a response. See selection bias. ;-) > . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
