Which process ensures every member of the population has an equal probability of selection?

Which process ensures every member of the population has an equal probability of selection?

• A. Survey population
• B. Sampling frame
• C. Pilot study
• D. Random sampling

Answer: (D)

This question tests how samples are chosen so that everyone has the same chance of being included. The method that guarantees equal probability for every member is random sampling. In random sampling, individuals are selected by a random process—like drawing names from a hat or using a computer-generated random number—to ensure each person in the population has the same chance of being chosen. This reduces selection bias and helps the sample reflect the population, at least in principle, though sampling error can still occur. Other terms describe parts of the process rather than the method of selection itself. The survey population refers to the group you want to learn about, not how you pick the sample. The sampling frame is the actual list or device you use to select members from; if it’s incomplete or biased, equal chances aren’t guaranteed. A pilot study is a small trial run to test questions and procedures, not a sampling method.

This question tests how samples are chosen so that everyone has the same chance of being included. The method that guarantees equal probability for every member is random sampling. In random sampling, individuals are selected by a random process—like drawing names from a hat or using a computer-generated random number—to ensure each person in the population has the same chance of being chosen. This reduces selection bias and helps the sample reflect the population, at least in principle, though sampling error can still occur.

Other terms describe parts of the process rather than the method of selection itself. The survey population refers to the group you want to learn about, not how you pick the sample. The sampling frame is the actual list or device you use to select members from; if it’s incomplete or biased, equal chances aren’t guaranteed. A pilot study is a small trial run to test questions and procedures, not a sampling method.