Which of the following is a reason for collecting specimens by random sampling in this type of research?

• A. Random sampling increases the probability that the specimens selected for the research study are representative of the population as a whole.
• B. Random sampling guarantees equal representation of all subgroups.
• C. Random sampling eliminates the need for statistical analyses.
• D. Random sampling makes data collection faster.

Answer: (A)

Random sampling is used to reduce selection bias and give each member of the population an equal chance of being included. This makes it more likely that the collected specimens reflect the population as a whole, which is essential when you want findings to generalize beyond the sample. While it increases the likelihood of representativeness, it doesn’t guarantee perfect representation of every subgroup—that would require a design like stratified sampling. It also doesn’t eliminate the need for statistical analysis, since researchers must still estimate sampling error and variability. And it doesn’t inherently make data collection faster; speed depends on how the sampling is carried out. So the best reason is that it increases the probability that the sample is representative of the population.