Which sampling method selects groups in proportion to their frequency in the population in order to obtain a representative sample?

Which sampling method selects groups in proportion to their frequency in the population in order to obtain a representative sample?

• A. Random Sampling
• B. Systematic Sampling
• C. Opportunity Sampling
• D. Stratified Sampling

Answer: (D)

Stratified sampling ensures the sample reflects the population by dividing the population into subgroups (strata) that share a defining characteristic (such as gender or age group) and then sampling from each subgroup in proportion to its size in the population. By doing this, the overall sample mirrors the population’s structure, so no subgroup is over- or under-represented, which improves the accuracy of findings across the different groups. Practically, you determine the population proportions for the chosen characteristics, create the strata accordingly, randomly sample from each stratum in those exact proportions, and combine the results. This approach provides representative coverage of the important subgroups, which random sampling alone does not guarantee and avoids potential pattern biases that systematic sampling could introduce.

Stratified sampling ensures the sample reflects the population by dividing the population into subgroups (strata) that share a defining characteristic (such as gender or age group) and then sampling from each subgroup in proportion to its size in the population. By doing this, the overall sample mirrors the population’s structure, so no subgroup is over- or under-represented, which improves the accuracy of findings across the different groups.

Practically, you determine the population proportions for the chosen characteristics, create the strata accordingly, randomly sample from each stratum in those exact proportions, and combine the results. This approach provides representative coverage of the important subgroups, which random sampling alone does not guarantee and avoids potential pattern biases that systematic sampling could introduce.