Which statement differentiates random error from systematic error?

Which statement differentiates random error from systematic error?

• A. Random error causes bias; systematic error causes scatter.
• B. Random error is unpredictable and causes scatter around a mean; systematic error causes consistent bias.
• C. Random error can be eliminated by calibration.
• D. Random error affects accuracy only; systematic error affects precision only.

Answer: (B)

Distinguishing how errors appear in measurement data is essential: random errors are unpredictable fluctuations that scatter repeated measurements around the true value, while systematic errors are consistent deviations in one direction that produce a bias. This also ties to accuracy and precision: random error reduces precision because results vary from trial to trial, whereas systematic error reduces accuracy because every measurement is consistently off from the true value. That’s why describing random error as unpredictable and causing scatter around a mean, and systematic error as causing a consistent bias, is the best choice. The other statements mix up bias and scatter, or claim calibration eliminates random error (calibration targets systematic error), or reverse which type affects accuracy versus precision.

Distinguishing how errors appear in measurement data is essential: random errors are unpredictable fluctuations that scatter repeated measurements around the true value, while systematic errors are consistent deviations in one direction that produce a bias. This also ties to accuracy and precision: random error reduces precision because results vary from trial to trial, whereas systematic error reduces accuracy because every measurement is consistently off from the true value.

That’s why describing random error as unpredictable and causing scatter around a mean, and systematic error as causing a consistent bias, is the best choice. The other statements mix up bias and scatter, or claim calibration eliminates random error (calibration targets systematic error), or reverse which type affects accuracy versus precision.