The control values for both controls for the prothrombin test were ranging between the mean and ±1 SD for the first 19 days of use.Starting on day 20,the values for both were consistently between +1 and +2 SDs.This is an example of a
A)shift.
B)trend.
C)random error.
D)predictable error.

Question

Quizplus · Accepted Answer

If all results are consistently different from the previous in the same direction,it indicates a shift in the methodology has occurred.A trend would show a gradual change over time.This is neither a predictable error nor a random error because it is consistent.

The Control Values for Both Controls for the Prothrombin Test