Every year ETS develops several TOEIC versions. Each version of the TOEIC test is validated on a population of at least 50,000 PEOPLE. It is therefore a highly reliable test, but no test measures performance with perfect accuracy and consistency.  
来源：考试大
 •  If a candidate takes another version of the TOEIC test, they will probably obtain slightly different scores from those they received the first time.  来源：考试大

 •  If they took several versions of the test within a short period of time, they would obtain a number of scores that center around an average value known as their "true" score. Two thirds of the time, their total score would be within 35 POINTS of their true score.