Why do pollsters most often rely on random sampling when conducting surveys?

• A. Because random sampling eliminates all sources of error in survey results.
• B. Because random sampling helps ensure that every member of the population has an equal chance of being selected, reducing selection bias.
• C. Because random sampling is always less expensive than other sampling methods.
• D. Because random sampling guarantees that the sample will perfectly match the population in all characteristics.

Answer: (B)

Verified step by step guidance

1. Understand that the goal of sampling in surveys is to obtain a representative subset of the population to make valid inferences about the whole population.
2. Recognize that random sampling means every member of the population has an equal chance of being selected, which helps avoid systematic biases in the selection process.
3. Know that random sampling reduces selection bias, which occurs when some members of the population are more likely to be chosen than others, potentially skewing results.
4. Be aware that while random sampling helps improve the representativeness of the sample, it does not eliminate all sources of error, such as measurement error or nonresponse error.
5. Conclude that pollsters rely on random sampling primarily because it promotes fairness in selection and helps ensure the sample is more likely to reflect the diversity of the population.