Question

Which of the following is the biggest advantage of simple random sampling ?

• A. Less sampling variance
• B. Freedom from human Bias
• C. Always gives a representative sample
• D. Can be used for large populations

Hint:

Think about what problem random selection solves compared to judgment-based selection, not about efficiency.

Answer 1

The Correct Option is B

Step 1: Check option (A). Simple random sampling (SRS) does not always give less sampling variance than other designs. Stratified or systematic sampling often produces lower sampling variance than SRS when the population has natural groupings, so (A) is not the defining advantage.

Step 2: Check option (C). Since SRS selects units purely by chance, it is possible, though unlikely, for a particular random draw to be unbalanced or unrepresentative. So SRS cannot guarantee representativeness in every single sample drawn, so (C) is false.

Step 3: Check option (D). For very large populations, SRS actually needs a complete and accurate list (sampling frame) of every unit, which is often impractical, so ease of use for large populations is not really an advantage of SRS.

Step 4: Check option (B). In SRS, every unit of the population has a known and equal chance of being selected, and the actual selection is done through a purely mechanical or random device (lottery, random number table), leaving no scope for the investigator's personal choice or judgment to affect which units enter the sample.

Step 5: This impersonal, objective nature of selection, that is, freedom from human bias, is precisely why SRS forms the basis of probability sampling theory. So the correct option is (B).