Opinion poll

An opinion poll, often simply referred to as a poll or a survey, is a human research survey of public opinion from a particular sample. Opinion polls are usually designed to represent the opinions of a population by conducting a series of questions and then extrapolating generalities in ratio or within confidence intervals. A person who conducts polls is referred to as a pollster.

November 3, 1948: President Harry S. Truman, shortly after being elected as President, smiles as he holds up a copy of the Chicago Daily Tribune issue prematurely announcing his electoral defeat. This image has become iconic of the consequences of bad polling data.