As used in marketing research, in which every member of universe or population has an equal chance of being selected. Not really random but very precise. An interval or probability sample. Names and addresses (every nth name) are chosen at regular intervals from a list such as a membership list. Gives a cross-section of population.

By law of averages, and because it is not subject to human error, more accurate than a quota sample. Interviewer required to make at least three attempts to locate a respondent before using a replacement. This, and more scattered location of respondents, makes random sample more expensive than quota sample.