A quota sample fails to represent the population when:

Answer

The quotas are mis-set, or the interviewer picks within them

Options - A. The quotas are mis-set, or the interviewer picks within them - B. The total sample is smaller than 30 units - C. The groups used to set the quotas are genuine strata of the population - D. The quotas are filled by a random draw Why - A. Correct — both are baked in: a mis-set quota mis-weights the groups, and within-quota selection is the interviewer's judgement. - B. Size affects precision; the failure of a quota sample is systematic and stays at any size. - C. Real strata are fine — the flaw is the non-random selection inside them, which is what separates quota from stratified sampling. - D. A random draw inside each group would make it a stratified sample, which does not have the flaw.

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