NOT a form of nonprobability sampling?

• A. Systematic random sampling
• B. Consecutive
• C. Convenience
• D. Judgmental

Answer: (A)

The main idea here is probability versus nonprobability sampling. A probability sampling method gives each member of the population a known, nonzero chance of being selected, which supports generalizability and the calculation of sampling error. The method that uses a random start and then selects every kth element is a textbook probability approach because every individual has a defined chance of inclusion.

Consecutive, convenience, and judgmental (purposive) sampling do not base selection on a random mechanism, so they are nonprobability methods. Consecutive sampling includes every eligible case in a set time frame, which can introduce bias because it depends on who happens to present during that window. Convenience sampling relies on what’s easy to access, leading to selection bias. Judgmental sampling chooses cases based on the researcher’s judgment, again lacking randomization and known inclusion probabilities.

Therefore, the method that is not a form of nonprobability sampling is systematic random sampling, since it provides randomization and known inclusion probabilities.