Quota Sampling

Quota sampling usually refers to the process whereby a researcher attempts to match in a sample the exact makeup of the population with regard to certain demographic characteristics deemed important (such as gender, age, race, income, etc.). For example, a researcher may strive to draw a sample from a population so that the sample consists of exactly 50% males and 50% females, certain percentages of persons from particular ethnic backgrounds, etc. The purpose of this practice usually is to achieve some kind of representative sample of the underlying population.

In general, only properly drawn probability samples such as EPSEM samples will guarantee that the population to which we want to generalize is properly "represented." Refer to, for example, Kish (1965) for a detailed discussion of the advantages and characteristics of probability samples (see also Representative Sample, Stratified Random Sampling, and Probability Sampling).

In STATISTICA, you can create probability (EPSEM) and stratified random samples using the Random Sampling options