Did you visit recently? A standard of deviation is the average variance from the average measurement (implying that you would have had multiple IQ tests done). For such a thing to be anything dramatic, your IQ scores would have been all over the place; further implying that the IQ tests given were not very accurate.
Ah a fellow statitics student.
The standard deviation is very simple: it is the square root of the variance. It is the most commonly used measure of spread.
The variance is computed as the average squared deviation of each number from its mean.
An important attribute of the standard deviation as a measure of spread is that if the mean and standard deviation of a normal distribution are known, it is possible to compute the percentile rank associated with any given score. In a normal distribution, about 68% of the scores are within one standard deviation of the mean and about 95% of the scores are within two standard deviations of the mean.
However, consistent with widespread inconsistent and ambiguous terminology, the square root of the bias-corrected variance is sometimes also known as the standard deviation.
If I had taken mutliple IQ tests, most certainly regression towards the mean would transpire, thus my true IQ range could, within a given confidence interval, be well establsihed.
Actually i have had my IQ tested in graduate school. I have a couple of advanced degrees in school counseling and school psychology, and before you take your individual intelligence testing courses, they offer to have you tested by another graduate student first, as once you learn the administration of the WAIS, Stanford Binet, etc. you really will never be able to get your own IQ accurately tested again.
