Why is random sampling used when collecting specimens for this type of population study?

• 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 speeds up data collection.
• C. Random sampling ensures every individual is included.
• D. Random sampling eliminates the need for controls.

Answer: (A)

Representativeness is the key idea. Random sampling gives every member of the population an equal chance to be selected, which helps ensure the group you study reflects the population as a whole. This reduces selection bias and makes the results more generalizable to the population. It does not guarantee that every individual is included—that would be a census—and it doesn't inherently speed up data collection; randomness can even complicate logistics. It also doesn't eliminate the need for controls—controls are about comparing treatments, not about who is sampled.