Using the grade equivalent composite scores on the Iowa Tests of Basic Skills of Iowa fourth grade public school pupils who took the tests in January 1970, a study was made to determine the relative precision with which an estimate could be made of the individual percentile norms from different types of cluster sample designs. Five scores ranging from the 14th to the 93rd percentiles were selected, and the proportions below these five scores became the proportions to be estimated. The variances of the estimates of these five proportions were computed for over 20 different sample designs; results from seven sample designs are presented. Using the error variances that were computed for each of the seven sample designs, the ratio of the error variance based on a cluster sample to the error variance based on a simple random sample of pupils was determined. (DB)