One of the criteria used in identification may be an IQ test score. Until the late 1960s, when “giftedness” was defined solely based on an IQ score, a school district simply set an arbitrary score (usually in the 130 range) and a student either did or did not “make the cut”. This method is still used by many school districts because it is simple and objective. Although a high IQ score is not the sole indicator of giftedness, usually if a student has a very high IQ, that is a significant indicator of high academic potential. Because of this consideration, if a student scores highly on an IQ test, but performs at an average or below average level academically, school officials may think that this issue warrants further investigation as an example of underachievement. However, scholars of educational testing point out that a test-taker's scores on any two tests may vary, so a lower score on an achievement test than on an IQ test neither necessarily indicates that the test-taker is underachieving nor necessarily that the school curriculum is under challenging.