Sampling probability

In the theory of finite population sampling, the inclusion probability of an element is its probability of becoming part of the sample during the drawing of a single sample.

Each element of the population may have a different probability of being included in the sample. The inclusion probability is also termed the first-order inclusion probability to distinguish it from the second-order inclusion probability, i.e. the probability of including a pair of elements.

Generally, the first-order inclusion probability of the ith element of the population is denoted by the symbol π_i and the second-order inclusion probability that a pair consisting of the ith and jth element of the population that is sampled is included in a sample during the drawing of a single sample is denoted by π_ij.

See also

• Sampling design

Further reading

• Sarndal, Swenson, and Wretman (1992), Model Assisted Survey Sampling, Springer-Verlag, ISBN 0-387-40620-4