Hmmm, strange. The last course I took (granted it was over ten years ago) on psychometrics rather strongly declared that tests results of beyond three standard deviations were well outside of the target range of most IQ tests... so much so that scores beyond three standard deviations were likely to be meaningless (since the margin of error in any score at the extremes of the test would likely be higher than the score differentials between standard deviations). We were encouraged to refer to scores in that range as “3 SDs +” as opposed to putting possibly fictional monikers or scores on these results. It could very well be the tests or their accuracy have changed in the intervening time... but I always raise an eyebrow when I hear scores much about 145 (based on that info)...
“The last course I took (granted it was over ten years ago) on psychometrics rather strongly declared that tests results of beyond three standard deviations were well outside of the target range of most IQ tests...”
I don't think I'd really disagree with that. The fact is, most tests that measure something like intelligence or aptitude don't even claim to measure beyond three SDs. My kids have taken any number of intelligence/aptitude tests that top out at 99%, which is about 2.6 SDs above the norm.
I remember when my older son was in Kindergarten, they gave all the kids an aptitude test. The teacher went over the results with each of us on an individual basis. There were five possible results for each subtest: average; below average; well below average; above average; and well above average.
So, I asked the teacher - are these standard deviations? Above average, below average, well above average, etc.? She asked, “What's a standard deviation?”
Education major.
I never saw the test before, but I guessed its ceiling was two standard deviations.
But the Wechsler, I think, tops out at 160, or four standard deviations, and I've never heard that it wasn't considered useful and accurate (with certain caveats applied) at that level.
I'm not aware specifically of other tests that might reach beyond that level. I left the field a long time ago, and the Wechsler was the test series with which I was familiar. However, folks in the field seem to test beyond that level, and though it may be tricky to get reliable metrics beyond a certain point, the problem is that there is something there to be measured, and so folks are going to try to measure it.
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