Recent developments in systematic sampling: A review

Systematic sampling is one of the most prevalent sampling techniques. The popularity of the systematic design is mainly due to its practicality. Compared with simple random sampling, it is easier to draw a systematic sample, especially when the selection of sample units is done in the field. In addition, systematic sampling can provide more precise estimators than simple random sampling when explicit or implicit stratification is present in the sampling frame. However, the systematic design has two major drawbacks. First, if the population size is not an integral multiple of the desired sample size, the actual sample size will be random. Second, a single systematic sample cannot provide an unbiased estimator for the sampling variance. Another limitation in the systematic design is that for populations with a periodic component, the efficiency of systematic sampling estimators will be highly dependent on the relation between the length of the period and the sampling interval. In the literature, one can find that many attempts have been made toward handling one or more of these issues. This article offers a review of the recent work in this area and provides some recommendations for survey practitioners using the systematic design for different sampling situations.