If a sampling frame is not available, which type of sampling can be used?

• A. Nonprobability sampling
• B. Probability sampling
• C. Systematic sampling
• D. Stratified sampling

Answer: (A)

When you don’t have a sampling frame, you use nonprobability sampling. A sampling frame is a complete list of the population from which you would draw your sample and it lets you know the chances of each member being selected. Without that list, you can’t perform probability-based methods that rely on known selection probabilities. Nonprobability approaches—such as convenience, snowball, or purposive sampling—don’t require a complete list or known odds, so they’re practical in this situation. Just keep in mind these methods can introduce bias and limit how well you can generalize results. Methods like systematic or stratified sampling depend on having a defined frame to select from, so they aren’t feasible without one.