Systematic Random Sampling The method of systematic random sampling (METHOD=SYS) selects units at a fixed interval throughout the sampling frame or stratum after a random start. PROC SURVEYSELECT ...

In an experiment, evaluate the validity of the steps leading up to the conclusion for it to be valid. Random and systematic errors can contribute to the uncertainty of a measurement.

Systematic and random sampling Systematic sampling means testing a hypothesis by taking several equally spaced items from a larger list, eg selecting the tenth, 20th and 30th visitor to a theme park.

W. G. Cochran, Relative Accuracy of Systematic and Stratified Random Samples for a Certain Class of Populations, The Annals of Mathematical Statistics, Vol. 17, No. 2 (Jun., 1946), pp. 164-177 ...