A Level Biology Practice Exam

What process does stratified sampling help improve in research?

1. Accuracy of random sampling

2. Formation of hypotheses

3. Comparative data analysis

4. Representation of sub-groups in the sample

The correct answer is: Representation of sub-groups in the sample

Stratified sampling is a method used in research to ensure that specific sub-groups within a population are adequately represented in the sample. By dividing the population into strata or distinct layers based on certain characteristics (such as age, gender, income level, etc.), researchers can then randomly sample from each stratum. This approach enhances the statistical power of the results and ensures that the findings are reflective of the entire population, rather than being skewed by the overrepresentation or underrepresentation of particular sub-groups. This targeted representation ultimately leads to more accurate and reliable conclusions when analyzing data related to those sub-groups, thereby improving the overall quality of the research findings.