Which category of error in measurements arises from human judgment or bias?

Which category of error in measurements arises from human judgment or bias?

• A. Personal error
• B. Natural error
• C. Instrumental error
• D. Calibration error

Answer: (A)

The main idea is that some measurement errors come from the observer’s actions and perceptions. When a measurement is affected by how a person reads, interprets, or records a value—say misreading a scale, reading from an angle (parallax), or rounding in a biased way—that’s personal error. It reflects human judgment or bias and can vary between people or even from one try to the next. Other categories are not about the observer: natural error is random variation inherent in the process, instrumental error comes from instrument imperfections or drift, and calibration error happens when the instrument isn’t properly aligned to a standard. So the error arising from human judgment or bias is personal error.

The main idea is that some measurement errors come from the observer’s actions and perceptions. When a measurement is affected by how a person reads, interprets, or records a value—say misreading a scale, reading from an angle (parallax), or rounding in a biased way—that’s personal error. It reflects human judgment or bias and can vary between people or even from one try to the next. Other categories are not about the observer: natural error is random variation inherent in the process, instrumental error comes from instrument imperfections or drift, and calibration error happens when the instrument isn’t properly aligned to a standard. So the error arising from human judgment or bias is personal error.