Principles of Sampling

Sampling is a complex discipline, yet it is of primary importance in many studies. Sampling methods for scientific study should be objective and should maximise accuracy of estimation. Scientific sampling is to provide a means of making inferences about the population of interest using observations made on the sample. There are two basic approaches to inference such as the design‐based approach, and the model‐based approach. With a much larger sample, it may be more difficult to find enough high‐quality interviewers and infeasible to brief them personally. The procedures and mechanisms that collectively constitute the method of sample selection are known as the sample design. Probability sampling or random sampling is often thought the only defensible selection method for serious scientific study unless it is simply not feasible. An important element of sample design is the determination of the sample size. Adaptive sampling is frequently used to sample rare or elusive populations.