Question

Suppose a scantron machine consistently grades students 4 points lower than their actual score. This scantron machine would be considered:

1) Unreliable and unbiased
2) Reliable and biased

Answer 1

The scantron machine is reliable because it consistently grades 4 points lower, but it is biased because it systematically deviates from the true score by not giving the correct value.

Step-by-step explanation:

If a scantron machine consistently grades students 4 points lower than their actual score, the consistency in error suggests that the machine is reliable, meaning it produces the same result under the same conditions. However, since it does not give the correct score, it is biased, as it systematically deviates from the true score. Therefore, the scantron machine would be considered reliable and biased.

Reliability in this context refers to the consistency of the scoring by the scantron machine. Bias refers to the systematic error that results in scores being 4 points lower than they should be. Despite its reliability, the machine's bias necessitates a calibration or correction to ensure accurate scoring.