What term describes how closely a measurement matches the true value?

What term describes how closely a measurement matches the true value?

• A. Calibration
• B. Precision
• C. Accuracy
• D. Standardization

Answer: (C)

Accuracy is about how close a measurement is to the true value. If a sample truly contains 50 mg/L of a substance and your reading is 49.8 mg/L, that measurement is accurate because it closely matches the actual amount. Precision, on the other hand, is about repeatability—the consistency of repeated measurements. You can be precise (measurements cluster tightly together) but not accurate if those measurements are all around 49.5 mg/L while the true value is 50 mg/L. Calibration is the process of adjusting an instrument to align its readings with known standards, which helps achieve accurate results. Standardization means using a consistent method so measurements are comparable across tests or labs. So, the term that best describes how closely a measurement matches the true value is accuracy.

Accuracy is about how close a measurement is to the true value. If a sample truly contains 50 mg/L of a substance and your reading is 49.8 mg/L, that measurement is accurate because it closely matches the actual amount. Precision, on the other hand, is about repeatability—the consistency of repeated measurements. You can be precise (measurements cluster tightly together) but not accurate if those measurements are all around 49.5 mg/L while the true value is 50 mg/L. Calibration is the process of adjusting an instrument to align its readings with known standards, which helps achieve accurate results. Standardization means using a consistent method so measurements are comparable across tests or labs. So, the term that best describes how closely a measurement matches the true value is accuracy.