In
statistics,
survey sampling describes the process of selecting a sample of elements from a target
population to conduct a survey. The term
"survey" may refer to many different types or techniques of observation. In survey sampling it most often involves a questionnaire used to measure the characteristics and/or attitudes of people. Different ways of contacting members of a sample once they have been selected is the subject of
survey data collection. The purpose of
sampling is to reduce the cost and/or the amount of work that it would take to survey the entire target population. A survey that measures the entire target population is called a
census.