Which sampling method is non-random?

• A. Convenience
• B. Simple random
• C. Systematic sampling
• D. Stratified sampling

Answer: (A)

Sampling methods that aim for representativeness use randomness. Convenience sampling, on the other hand, selects individuals based on who is easiest to access, with no random process determining inclusion. This means there isn’t a known, equal chance for each population member to be included, making it a non-random (non-probability) approach. It’s fast and inexpensive, but it biases the sample toward easily reachable groups and limits how safely we can generalize findings.

In contrast, the other methods rely on random selection. Simple random sampling gives every member an equal chance of selection. Systematic sampling chooses every kth person after a random starting point, which preserves a random element. Stratified sampling divides the population into subgroups and randomly samples within each, ensuring representation across subgroups. These are all random methods, improving generalizability compared to convenience sampling.