ABSTRACT
D. Siniff and R. O. Skoog used stratified random sampling to estimate the size of the Nelchina herd of Alaska caribou in February of 1962. In January and early February, several sampling techniques were field-tested. Taking a stratified sample can provide some balance in the sample on the stratifying variable. The field tests told the investigators that several of the proposed sampling units, such as equal-flying-time sampling units, were difficult to implement in practice, and that an equal-area sampling unit of 4 square miles would work well for the survey. The American Council of Learned Societies (ACLS) used a stratified random sample of selected ACLS societies in several disciplines to study publication patterns and computer and library use among scholars who belong to one of the member organizations of the ACLS. Stratification is most efficient when the stratum means differ widely; then the between sum of squares is large, and the variability within strata will be smaller.
