Sample Surveys

Incorrect polling techniques used during the 1936 presidential election led to the demise of the popular magazine, The Literary Digest.

In the 1948 presidential election, the use of quota sampling led the polls to inaccurately predict that Dewey would defeat Truman.

When conducting a survey, a sample can be chosen by chance or by more methodical methods.

Even when using probability sampling methods, bias can still occur.

The Gallup Poll is a public opinion poll that conducts surveys in 140 countries around the world.

Telephone surveys can reach a wide range of people very quickly and very inexpensively.

Chance error and bias are two different forms of error associated with sampling.