Which statement best describes the purpose of random selection when selecting multiple units for testing?

Which statement best describes the purpose of random selection when selecting multiple units for testing?

• A. To maximize testing of the units with the most lead risk.
• B. To test only newer units.
• C. To ensure the selection is not biased by preconceived notions or convenience.
• D. To eliminate the need for testing common areas.

Answer: (C)

Using random selection ensures the testing process is objective and unbiased. When each unit has an equal chance of being chosen, you avoid letting personal judgment or convenient sampling influence which units get tested. This makes the test results more representative of all units and more defensible in showing how lead risk appears across the population, not just in projects you happen to inspect. The statement that best captures this purpose is that the selection is not biased by preconceived notions or convenience. Focusing on the most risk-heavy units would introduce bias, testing only newer units ignores the rest, and removing testing of common areas doesn’t relate to how units are chosen in the random process.

Using random selection ensures the testing process is objective and unbiased. When each unit has an equal chance of being chosen, you avoid letting personal judgment or convenient sampling influence which units get tested. This makes the test results more representative of all units and more defensible in showing how lead risk appears across the population, not just in projects you happen to inspect. The statement that best captures this purpose is that the selection is not biased by preconceived notions or convenience. Focusing on the most risk-heavy units would introduce bias, testing only newer units ignores the rest, and removing testing of common areas doesn’t relate to how units are chosen in the random process.