ABSTRACT
A stratified sampling design purposely partitions the target population, P , into two or more non-overlapping subpopulations, called strata, which are sampled separately. In this chapter we present the rationale for stratified sampling and estimators for the population total, y , and related population parameters, as well as corresponding estimators for the individual strata. A design issue which arises with stratified sampling is the allocation of the overall sampling effort to the various strata, a topic which is addressed following the section on estimation. The sections at the end of the chapter discuss matters related to stratified sampling: incorrect strata assignment, double sampling for stratification, and poststratification.
