What is the preferred sampling method described?

• A. Haphazard.
• B. Random.
• C. Systematic selection - random first item and then every nth item.
• D. Judgmental.

Answer: (C)

Systematic sampling with a random start combines structure with randomness to give a well-spread sample. By choosing the first item at random and then selecting every nth item, you cover the entire population rather than clustering in one area or biasing toward the beginning or end. This approach is efficient and easy to implement in audits: you set an interval based on population size and desired sample size, then proceed through the list in fixed steps. The random starting point helps avoid bias that could come from the order of the items, making the sample more representative overall.

Purely haphazard or judgmental sampling relies more on the auditor’s discretion and can introduce selection bias. Pure random sampling is unbiased but can be less practical in large populations and may not guarantee even coverage across the whole file, whereas systematic sampling with a random start achieves both representativeness and efficiency, provided the interval isn’t aligned with any hidden pattern in the data.