We can measure the level of IQ through the Wei's Intelligence Test. Such a test will have a norm. Those who are two standard deviations above or below the standard will be targeted by special education.
We can use the Weiss Intelligence Test to measure the level of intelligence, and such a test will have a norm where both the upper and lower standard deviations are served by the Special Education Association.
We can measure the IQ by the Wechsler intelligence test, which will have a norm, and the standard or the next two standard deviations will be the objects served by the special education society.