Which sampling method is designed to ensure that subgroups are represented in proportion to their size in the population?

Which sampling method is designed to ensure that subgroups are represented in proportion to their size in the population?

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

Answer: (A)

Stratified sampling is designed to ensure subgroups are represented in proportion to their size in the population. It works by creating separate groups (strata) based on a relevant characteristic, like age or gender, and then sampling from each stratum in proportion to that group's share of the population. This keeps the overall sample reflective of the population's structure and reduces the risk that important subgroups are under- or over-represented. In contrast, random sampling gives equal chance to all individuals but doesn’t guarantee proportional representation of subgroups; systematic sampling selects every nth person from a list without addressing subgroup sizes; volunteer sampling relies on who volunteers and can bias the sample toward certain traits, not reflecting population proportions.

Stratified sampling is designed to ensure subgroups are represented in proportion to their size in the population. It works by creating separate groups (strata) based on a relevant characteristic, like age or gender, and then sampling from each stratum in proportion to that group's share of the population. This keeps the overall sample reflective of the population's structure and reduces the risk that important subgroups are under- or over-represented.

In contrast, random sampling gives equal chance to all individuals but doesn’t guarantee proportional representation of subgroups; systematic sampling selects every nth person from a list without addressing subgroup sizes; volunteer sampling relies on who volunteers and can bias the sample toward certain traits, not reflecting population proportions.