Question

When you visit the doctor's office several measurements may be taken, one of which is your weight. A doctor's office encourages patients to keep their shoes on to be weighed and promises to subtract 2 pounds for the weight of the patient's shoes. Which of the following is true once the patient's weight is adjusted by 2 pounds? and Why?

(a) This will be a reliable measure of the patient's weight.
(b) This will be a valid measure of the patient's weight.
(c)This will be unbiased measure of the patient's weight.
(d) None of the above is true.

Answer 1

This will be an unbiased measure of the patient's weight because the patient's shoes will add a fixed amount of weight (2 lbs) regardless of how much the patient weighs. As such, the adjustment will be equally valid for all patients, which makes it an unbiased measure.

However, it will not be a valid measure because the adjusted weight will not be an accurate measure of the patient's true weight (due to the subtracted amount).

This will also not be a reliable measure of the patient's weight because the subtracted weight will introduce unwanted error.