Gallup At its website (www.gallup.com), the Gallup Poll publishes results of a new survey each day. Scroll down to the end, and you’ll find a statement that includes words such as these:
Results are based on telephone interviews with 1016 national adults, aged 18 and older, conducted July 7–10, 2011. . . . In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
a) For this survey, identify the population of interest.
b) Gallup performs its surveys by phoning numbers generated at random by a computer program. What is the sampling frame?
c) What problems, if any, would you be concerned about in matching the sampling frame with the population? In exercises 17 to 23, for the following reports about statistical studies, identify the following items (if possible). If you can’t tell, then say so—this often happens when we read about a survey.
a) The population
b) The population parameter of interest
c) The sampling frame
d) The sample
e) The sampling method, including whether or not randomization was employed
f) Who (if anyone) was left out of the study.
g) Any potential sources of bias you can detect and any problems you see in generalizing to the population of interest