Edited sentence: " still enjoys colloquial usage, and is used to describe all of the intelligence scales currently in use.In addition, IQ tests like the Wechsler were not intended to discriminate reliably much beyond IQ 145, as ceiling effects become a concern.Modern scores are sometimes referred to as "deviance IQ", while older method age-specific scores are referred to as "ratio IQ.Since the publication of the Wechsler Adult Intelligence Scale (WAIS), almost all intelligence scales have adopted the normal distribution method of scoring.The modern IQ score is a mathematical transformation of a raw score on an IQ test, based on the rank of that score in a normalization sample.The two methodologies yield similar results near the middle of the bell curve, but the older ratio IQs yielded far higher scores for the intellectually gifted— for example, Marilyn vos Savant, who appeared in the Guinness Book of World Records, obtained a ratio IQ of 240.The use of the normal distribution scoring method makes the term "intelligence quotient" an inaccurate description, mathematically speaking, of the intelligence measurement, but "I.While this score could make sense using Binet's formula using the ratio of mental age over chronological age (and even then, only for a child), on the Gaussian curve model it would be an exceptional 7.9 standard deviations above the mean and hence highly improbable in a population the size of the human population with a normal IQ distribution (see normal distribution)