Systematic error can best be described as consisting of

Systematic error can best be described as consisting of

• A. Constant and proportional error.
• B. Constant error.
• C. Proportional error.
• D. Random error.

Answer: (A)

Systematic error is a repeatable bias that shifts all measurements in a predictable way. It can have two components: a constant bias, which adds or subtracts the same amount to every reading, and a proportional bias, which scales with the true value so the error grows proportionally with the measurement. Together, these describe a bias that is both fixed in size and dependent on magnitude, which is why constant and proportional error is the best description. For example, a calibration offset that always adds 2 units to every result represents the constant part, while a method that overestimates by 5% across the board represents the proportional part. If a method exhibits only a fixed offset, or only a percentage error, it would not fully capture all systematic biases. Random error, by contrast, varies unpredictably from one measurement to the next and is not reproducible in a consistent direction.

Systematic error is a repeatable bias that shifts all measurements in a predictable way. It can have two components: a constant bias, which adds or subtracts the same amount to every reading, and a proportional bias, which scales with the true value so the error grows proportionally with the measurement. Together, these describe a bias that is both fixed in size and dependent on magnitude, which is why constant and proportional error is the best description.

For example, a calibration offset that always adds 2 units to every result represents the constant part, while a method that overestimates by 5% across the board represents the proportional part. If a method exhibits only a fixed offset, or only a percentage error, it would not fully capture all systematic biases. Random error, by contrast, varies unpredictably from one measurement to the next and is not reproducible in a consistent direction.