Sampling Design For Successive Survey And It's Application

Objective: For the survey of population's value, variation, accumulative total and the average, we need successive survey, which is the main body of our country's survey system. To use the fixed sample time after time, there are two serious problems of that one is the reduction of sample representation, another one is sample fatigue. However, using completely new sample in each survey also has several problems. Firstly, it couldn't reflect the change of population in continuous time. Secondly, we couldn't employ the combined regression estimation without the prior period data of fixed sample by which the estimate precision is better than that of common one. Thirdly, comparing with fixed sample, completely new sample need more cost and time. To balance these two aspects, statisticians have excogitated the good method of sample rotation (under the same sample size, we replace part of the sample units each survey). For sample rotation, it retains some of the original units and add some new sample units, so it assembled the advantages of both the fixed sample and completely new sample, striking the balance between sampling cost and sampling precision. It was the means to reduce and control non-sampling error, unifying the sampling efficiency and sampling precision.The key of sampling survey is sampling design. Sampling design for single survey (transect survey) is widely researched at home and abroad, of which theories and methods are relatively mature. However, for sampling design of successive survey, the research for sample rotation is mainly confined to the simple random sample survey. It is very few that the research for sample rotation of successive survey under complicated sampling methods. So, in this paper, we deduced the formulae for relevant statistic under stratified simple random sampling, cluster sampling, stratified cluster sampling, two-stage sampling and stratified two-stage cluster sampling for sample rotation of successive survey, filled the corresponding gap. Moreover, the practical application was explored.Methods: The theories of stratified sampling, cluster sampling, two-stage sampling, regression estimate, ratio estimate, successive survey, sample rotation and probability statistic were employed for the design and formula deduction. During the practical application of sampling methods and the deduced formulae, we employed the survey methods of stratified simple random sampling, cluster sampling, two-stage sampling, stratified cluster sampling, stratified two-stage cluster sampling, and also the methods of medical physical examination and questionnaire survey.Results: For the sample rotation of successive survey, under the five complicated sampling methods of stratified simple random sampling, cluster sampling, two-stage sampling, stratified cluster sampling, stratified two-stage cluster sampling, we deduced the formulae for combined estimate of population mean as well as its variance, for the estimate of variance, for the optimum sample rotation rate and for the optimum weight. Meanwhile, we conducted two sampling surveys. One is the sampling survey of staff's body mass index (BMI) of Daya Bay Nuclear Power Operation and Management Co.,Ltd (DNMC) in Guangdong in the years 2005-2007 for three times consecutively. The other one is the sampling survey of students'cheating frequency in examination in new campus of Soochow University in the years 2006-2007 for two times consecutively. Then these deduced and proved formulae were applied to the parameter estimation, moreover, the sampling precision was detected. As to the sampling precision, the method of sample rotation comparing with that of fixed sample for successive survey, it was 29.5 times higher for stratified simple random sampling, 5 times higher for cluster sampling, 3.2 times higher for stratified cluster sampling, 24 times higher for two-stage sampling and 18 times higher for stratified two-stage cluster sampling. That was to say, the sampling precision were several times higher or even tens times higher for sample rotation than for fixed sample. The application result of these deduced and proved formulae was very good. Conclusion: During this study, for the sample rotation of successive survey under the five complicated survey methods, the corresponding formulae deduced and proved for calculating statistic are scientific, by which the estimated precision is highly increased. This study is originality innovation and significant of theory and reality.