Measurement error is defined as?

Measurement error is defined as?

• A. The discrepancy between the numbers used to represent the thing being measured and the actual value.
• B. The systematic bias that affects all measurements in the same direction.
• C. The difference between observed and predicted values.
• D. The variance of the measurement instrument.

Answer: (A)

Measurement error is the discrepancy between the numbers used to represent the thing being measured and the actual value of that thing. In practice, we think of an observed value as the true value plus some error, meaning no measurement is perfect. This matches the idea that the measured value differs from the true value by an amount we call error. The other descriptions refer to related ideas but aren’t the full definition: systematic bias describes a consistent direction of error, not the general discrepancy; the difference between observed and predicted values is about model residuals rather than measurement itself; and the instrument’s variance concerns precision of repeated measurements, not the error relative to the true value.

Measurement error is the discrepancy between the numbers used to represent the thing being measured and the actual value of that thing. In practice, we think of an observed value as the true value plus some error, meaning no measurement is perfect. This matches the idea that the measured value differs from the true value by an amount we call error. The other descriptions refer to related ideas but aren’t the full definition: systematic bias describes a consistent direction of error, not the general discrepancy; the difference between observed and predicted values is about model residuals rather than measurement itself; and the instrument’s variance concerns precision of repeated measurements, not the error relative to the true value.