BALANCED REPEATED REPLICATIONS BASED ON ORTHOGONAL MULTI-ARRAYS

To obtain variance estimates in stratified sampling with possibly uneq ual numbers of primary sampling units per stratum, one can either rand omly divide the units in each stratum into two groups and apply the ba lanced half-samples method to these groups, or use mixed orthogonal ar rays to form a set of balanced subsamples. With the first technique, r esulting variance estimates can be very inefficient, and with the seco nd technique it can be difficult to construct orthogonal arrays with a small number of replicates for a given stratified design. The propose d extension of the orthogonal array method to orthogonal multi-arrays retains all of the orthogonal array method's desirable properties but allows greater flexibility in construction, and thus can handle more c omplex stratified designs using fewer replicates.