Post-Stratification
Post-stratification is the adjustment of weights such that weighted estimates of characteristics match known population parameters. Because these characteristics were not available for sample design, the inverse probability of selection does not reflect them.
Contents
Variance
The degrees of freedom for post-stratified variance is commonly approximated as the number of PSUs (n) minus the number of strata (H). This formally is a special case of the Satterthwaite approximation.