Area Probability Sample

An area probability sample is one in which geographic areas are sampled with known probability. While an area probability sample design could conceivably provide for selecting areas that are themselves the units being studied, in survey research an area probability sample is usually one in which areas are selected as part of a clustered or multi-stage design. In such designs, households, individuals, businesses, or other organizations are studied, and they are sampled within the geographical areas selected for the sample. An example of a survey that uses area probability sampling in the United States is the Current Population Survey (CPS).