The process of drawing a sample is completed in several stages and such type of sampling is known as multi-stage sampling.
Suppose we want to estimate the yield of wheat per acre of land in our country. The basic unit of collecting information in this regard is the crop field. For selecting some fields, we proceed as under. At the first stage, we select some districts at random from among the wheat growing districts in the country. At the second stage, we, then select some blocks from among the districts selected at the first stage. Finally from the blocks thus selected, we select some fields and collect information there from for estimating the yield of wheat per acre of land.