It is well known among businessmen, that the reaction of the public toward a given product or service, can be fairly accurately estimated by making samples inquiries among the relevant customers.  This device is being applied to the science of government.  In the United States, promising strides have been made by public opinion polls like the American Institute of Public Opinion, Crossley and ’Fortune Magazine.’ 
 
            Exhibit 7.1
              Polling Techniques
             
            7.1a 	Polling Techniques
            
            The polling technique was extended to elections 
              by collecting what were known as straw votes from small portions 
              of the electorate. For example in 1936, the Literary Digest attempted 
              to collect straw votes by sending ballots through the mail 
              to people whose names were taken randomly either from telephone 
              directories or from lists of automobile owners. This resulted in 
              gross miscalculation because the sample did not include people who 
              did not own telephones or cars. Some of them did not even return 
              the ballot.
            There are several polls that try to make election 
              predictions, of which the best known is the one conducted by George 
              Gallup, for the American Institute of Public Opinion. The accuracy 
              of the results of the poll depends on securing a sample representative 
              of the total universe, that is the whole group whose 
              opinion is being sought. If each unit in a universe is equally included, 
              then even a small sample can give accurate results. Beyond a certain 
              point, if there is an increase in the size of the sample, the chances 
              of a reduced number of sampling errors are greater. (A sampling 
              error is the range existing between divisions in the sample and 
              those of the universe.)
            Drawing the sample at random would be one way of 
              developing a representative sample. However this kind of random 
              sampling is impossible for most political surveys. Instead census 
              tracts are used, giving the number of residences and their locations. 
              Quota sampling is a less complicated sample, though it is 
              less reliable. In this type of poll, an attempt is made to secure 
              a sample reflecting the variables among the population that can 
              affect opinion.
 
            7.1b 	Avoiding biased samples
            In many cases conclusions may happen to be based 
              on biased samples. For example a reporter may write that students 
              are becoming more conservative, after interviews with a dozen students 
              on the Yale campus. In general the success of opinion polls depends 
              on the accuracy of the sample rather than on the number of persons 
              interviewed. It is important for the sample to represent a cross 
              section. The error in the polls should not exceed three percent. 
              The neutral wording of the questions is also important, as pointed 
              questions can elicit pointed replies. Voters may also be interviewed 
              after they have cast their votes. This is known as exit polls, 
              which are also an aid to the candidate to estimate the respective 
              areas of his weakness and strength and to adjust his campaign techniques 
              accordingly.
            It cannot be denied that in spite of the difficulties 
              involved in polling, it is such a useful device that it is used 
              by various organizations. Parties conduct polls during elections 
              to find out their strong and weak points. In fact, polls are an 
              essential art of the American politics. The news media carry out 
              surveys and even the polling organizations are involved in this 
              task. Polls are also run by interest groups to support their claims 
              that the people are in favor of or in opposition to a certain policy.