Which method requires that the target population be in a natural order for sampling?

Systematic random sampling is the method that requires the target population to be in a natural order for sampling. This technique involves selecting elements from an ordered sampling frame at regular intervals, which can only be effectively enacted if there is a clear sequence or arrangement within the population. This might involve numbering elements and then using a fixed interval (like every 10th person) for selection. The presence of a natural order allows for systematic and unbiased selection of samples, which enhances the representativeness of the sample.

In contrast, simple random sampling does not require any specific order among the population; it involves randomly selecting individuals without consideration of their arrangement. Similarly, stratified random sampling divides the population into subgroups (strata) to ensure that specific sections are adequately represented but does not depend on any inherent ordering. Categorical sampling is not a standard term associated with formal sampling methodologies in statistics. Overall, systematic random sampling uniquely hinges on the necessity of an ordered population, setting it apart from the other methods.