Simple Random Sample

There are two varieties of simple random samples: (1) with replacement and (2) without replacement. To draw a simple random sample, one must have a frame drawn up for the population of interest prior to sampling or at least know the size of the frame in advance. For a simple random sample without replacement, all

possible subsets of n units have equal probability of selection. For a simple random sample with replacement, all Nnn-tuples of units have equal probability of selection. Although simple random samples are rarely used in sample surveys, they have played an important role in the development of the epistemologi-cal theory for survey research, and they continue to be useful in pedagogy, as an efficiency benchmark, and as a proving ground ...