With reference to sampling, which of the following are correct?
(A) Simple random sampling is probability sampling
(B) Snow-ball sampling is non-probability sampling
(C) Stratified sampling is probability sampling
(D) Cluster sampling is non-probability sampling
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A), (B) and (C) only
In probability sampling, the units are selected by a random process, so every unit has a known, non-zero chance of selection. In non-probability sampling, the units are chosen by judgement, convenience or referral.
So simple random, stratified and cluster sampling are probability methods, and snowball sampling is a non-probability method.
Checking the statements
(A) Simple random sampling is probability sampling — Correct. Every unit has an equal chance of selection.
(B) Snow-ball sampling is non-probability sampling — Correct. Each respondent refers the next ones; there is no random selection.
(C) Stratified sampling is probability sampling — Correct. A random sample is drawn from every stratum.
(D) Cluster sampling is non-probability sampling — Incorrect. Whole clusters are chosen at random, so it is probability sampling.