Complex Sample Surveys

Complex sample surveys involve the identification and data collection of a sample of population units via multiple stages or phases of identification and selection. In contrast, a simple sample survey design involves a simple random sample, where there is a list of the elements of the population and a certain number of these elements is selected by drawing one at a time. The classic textbook example is when each element of the frame is numbered from 1 to N (i.e. population size) and then n (i.e. sample size) elements are drawn using a table of random numbers. By contrast, complex sample surveys may rely on stratification, clustering, multi-stage or multi-phase designs, unequal probability sampling, or multi-frame sampling. These techniques often reduce the cost of data ...