Despite his success in 1936, George Gallup failed miserably in trying to predict the winner of the 1948 U.S. presidential election. His organization, as well as two others, predicted that Thomas Dewey would beat incumbent Harry Truman. All three used what is called quota sampling. The interviewers were told to find a certain number, or quota, of each of several types of people.
For example, they might have been told to interview six women under age 40, one of whom was African American and the other five of whom were Caucasian.
Imagine that you are one of their interviewers, trying to follow these instructions. Whom would you ask? Now explain why you think these polls failed to predict the true winner and why quota sampling is not a good method.