Simple Random Sampling
Steven K. Thompson · Wiley series in probability and statistics · 2012
Simple random sampling, or random sampling without replacement, is a sampling design in which n distinct units are selected from the N units in the population in such a way that every possible combination of n units is equally likely to be the sample selected. This chapter begins with a discussion of selecting a simple random sample. With simple random sampling, the sample mean is an unbiased estimator of the population mean. Also with simple random sampling, the sample variance is an unbiased estimator of the finite-population variance. The chapter then discusses random sampling with replacement. It presents derivations for random sampling and describes model-based approach to sampling. The chapter finally illustrates simple computations for sampling using the open-source statistical programming language R. Controlled Vocabulary Terms estimator; mean; random sampling; variance