In 1936 the United States was still suffering from the Great Depression. During the presidential election campaign, an extensive survey of voter attitudes was undertaken to find out whether the public preferred the incumbent, Franklin Delano Roosevelt, or the challenger, Alf Landon. The sample was gathered randomly from telephone book listings throughout the country. A preference was found for Alf Landon; however, Roosevelt won re-election by a huge landslide. What type of research was being conducted? Why do you think it failed to make an accurate prediction?