Variable probability sampling selects members of the population proportional to an auxiliary variable. If the auxiliary variable is based on membership in subgroups, then it is similar to stratified sampling, except that the number of samples allocated to a subgroup is not fixed but random.
The variance is the mean square deviation of the variable around the average value. It reflects the dispersion of the empirical values around its mean. OECD Source: Eurostat, "Assessment of Quality in Statistics: Glossary", Working Group, Luxembourg, October 2003.
The total variation displayed by a set of observations, as measured by the sums of squares of deviations from the mean, may in certain circumstances be separated into components associated with defined sources of variation used as criteria of classification for the observations. Such an analysis is called an analysis of variance, although in the strict sense it is an analysis of sums of squares. Many standard situations can be reduced to the variance analysis form. OECD Source: A Dictionary of Statistical Terms, 5th edition, prepared for the International Statistical Institute by F.H.C. Marriott. Published for the International Statistical Institute by Longman Scientific and Technical.
Variable probability sampling
