How does the pollster decide who to call?
All polls are based on the idea of a random sample. Two methods are used to get the sample. The first is called RDD (Random Digit Dialing) in which the pollster carefully chooses an area code and prefix (together. the first six digits of a telephone number) and then picks the next four digits at random. Because of how the telephone is organized, people with the same first six digits generally live close together, although this property is changing. This method generates a good random sample since it hits all in the selected area with equal probability, including unlisted numbers. Unfortunately, it also hits business phones, fax machines, and modems. The second method takes telephone numbers from a telephone book or list and uses them or sometimes randomizes final digit to hit unlisted numbers.
