Learn how to avoid response bias by using a method of randomized response. The method assures anonymity of subjects' answers, so encourages truthful responses to sensitive questions. Organization and Planning Obtain a coin, a standard pencil, and uniformly-sized and colored slips of paper for each subject. Devise a list of questions with socially desirable answers, answers which the subjects are biased toward because of societal norms. Objectives Students review how bias can make samples non-representative.
Students develop a deeper understanding of how to assure samples are representative.
Students review the fact that larger random samples generally yield results that more nearly represent the population. Procedures Subjects flip a coin, keeping the results secret. Collect the slips of paper, and discard all but the slips marked 1 or 0. Place slips with 1 in a pile, and slips with 0 in a separate pile. Find the ratio of 1s to the total of 1s and 0s to calculate the percentage of the sample that answered yes.