SURVEYSELECT Procedure
The SURVEYSELECT procedure provides a variety of methods for selecting probabilitybased random samples. The procedure can
select a simple random sample or can sample according to a complex multistage sample design that includes stratification,
clustering, and unequal probabilities of selection. With probability sampling, each unit in the survey population has a known,
positive probability of selection. This property of probability sampling avoids selection bias and enables you to use statistical
theory to make valid inferences from the sample to the survey population. The following are highlights of the SURVEYSELECT procedure's
features:
 selects the sample and produces an output data set that contains the selected units, their selection probabilities, and their sampling weights
 provides methods for both equal probability sampling and probability proportional to size (PPS) sampling
 provides the following equal probability sampling methods:
 simple random sampling
 unrestricted random sampling (with replacement)
 systematic random sampling
 sequential random sampling
 Bernoulli
 provides the following unequal probability sampling methods:
 provides the following probability proportional to size (PPS) methods:
 PPS sampling without replacement
 PPS sampling with replacement
 PPS systematic sampling
 PPS algorithms for selecting two units per stratum
 sequential PPS sampling with minimum replacement

 performs stratified sampling by selecting samples independently within the specified strata, or nonoverlapping subgroups of the survey population
 enables you to sort by control variables within strata for the additional control
of implicit stratification when using a systematic or sequential selection method
 provides survey design methods to allocate the total sample size among the strata
 provides the following allocation methods: proportional, Neyman, and optimal allocation
 provides replicated sampling, where the total sample is composed of a
set of replicates, and each replicate is selected in the same way
 enables you to randomly assign the observations in the input data set to groups

For further details see the SAS/STAT User's Guide:
The SURVEYSELECT Procedure
( PDF  HTML )
Examples