Department of Statistics, University of Waikato

2003-05-26

Room I1.09, University of Waikato

This talk will derive a simple explicit formulae for the optimal sizes of samples that should be taken in stratified sampling when the strata variances are known. The optimal sample sizes are chosen so as to minimise the overall variance of the sample statistic, whilst remaining within a given sampling budget. The derivation of the sample sizes ignores that they are integers, under the assumption that rounding will give near optimal values. The results are compared with those from dynamic programming and non-linear integer programming algorithms which take the integer requirements into account.