Question

Which of the following would decrease bias when selecting a sample for a controversial political survey?

A. survey only registered voters
B. conduct the survey on the Internet
C. advertise for participants on talk radio
D. ensure that individual responses are confidential

Answer 1

The correct option is A.
In survey sampling, bias is defined as the tendency of the chosen sample to over estimate or under estimate a population parameter. Bias is said to occur when the used sample does not accurately represent the population concerned; a good sample should be representative. There are different types of bias, depending on how they arise. When selecting a sample for controversial political survey, choosing participants from registered voters only will decrease the bias of the sampling.