Topic explanation

Standard explanation

Accuracy describes how closely a measured value agrees with the true or accepted reference value.

Key points

• Define measurement accuracy and precision.
• Distinguish accuracy from precision.
• Accuracy requires comparison with a reference value.
• Precision requires repeated measurements.
• A precise measurement is not necessarily accurate.
• Resolution is not precision.
• Error equals measured value minus reference value.
• Bias equals mean minus reference value.

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