Section 26(6)(b) in The Orissa Statistics and Economics Service Rules, 1979
(b)Applied statistics. - Use of sampling methods in censuses and surveys-The requirements of a good sample, avoidance of basis in selection methods of reducing the sampling error. Structure of various types of samples-Random sample, stratification with uniform sampling fraction, multiple stratification, stratification with a variable sampling fraction, systematic samples. Multistage sampling, balanced samples. Sub-sampling and repetitive surveys. Interpenetrating sub-samples. Estimation of mean and population total in respect of these processes.