Comment by kf | Hacker News Reader

Comment by kf | Hacker News Reader

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Yes, because the group IQ tests are lumped in with achievement tests kids often have no idea that it is different from the other achievement tests, whereas the psychologist tests certainly stand out. Looks like NYC public schools recently adopted a group IQ test after years of using the real thing... http://en.wikipedia.org/wiki/Otis-Lennon_School_Ability_Test

Also see this comment from Ronald Hoeflin (an author of multiple super IQ tests) about verbal intelligence. http://www.eskimo.com/~miyaguch/ultra.html

>A comment on verbal intelligence: Some people wonder about the value of verbal items as a measure of "intelligence," since trying such items seems to involve little or no intellectual effort. From the purely statistical standpoint, many studies repeatedly showed that verbal intelligence, including the sheer size of one's vocabulary, has one of the highest correlations of any type of test item with overall intelligence as measured by tests containing a wide variety of test items. See for example the book Intelligence in the United States, published around 1958, for ample documentation. On the purely intuitive level, one might say that learning a language, including vocabulary, is for the child like decoding hieroglyphics. The brighter child will master this decoding process far more readily than the average child. Later, of course, one can artificially boost the size of one's vocabulary, but cleverly designed tests of verbal intelligence can get around this problem by relying on somewhat atypical verbal items that one would be unlikely to pick up through a "vocabulary improvement" course but that a gifted child would be likely to have picked up if he has been reasonably inquisitive -- and isn't inquisitiveness an important part of intelligence? Finally, to use a computer analogy, a powerful computer without adequate software (analogous to verbal intelligence in humans) would be relatively unproductive no matter how powerful the hardware. -- RKH

He has one more test that is publicly posted. http://www.eskimo.com/~miyaguch/titan.html

"From the purely statistical standpoint, many studies repeatedly showed that verbal intelligence, including the sheer size of one's vocabulary, has one of the highest correlations of any type of test item with overall intelligence as measured by tests containing a wide variety of test items."

I call bullshit. Hart & Risley found that by far the biggest predictor of verbal ability was the volume of language used by the parents. IQ had only a nominal correlation.

NONE of the "uncommonly difficult IQ tests" mentioned on that very interesting site have ever been properly validated.

Out of interests sake: how does one validate an IQ test?

Out of interests sake: how does one validate an IQ test?

Thanks for asking the important follow-up question that is so rarely asked. To validate an IQ test (a test that purports to estimate "general intelligence"), one must first reach a consensus among test designers about some sign of intelligence that is detectable outside the testing room. Over the years, psychologists have proposed various behavioral characteristics of human beings as signs that those human beings are "intelligent," with entering challenging, high-income occupations that require a lot of higher schooling being one criterion proposed for adult IQ tests, and being precocious in school and having good grades and good teacher ratings being one criterion that is proposed for child IQ tests.

One finds a sample of persons to take a new brand of test in its norming administration, and rates those persons by external criteria of "intelligence," weighting those criteria by consensus, and then checks the rank-order correlation between the ranking of the test-takers yielded by the IQ test and the ranking of the test-takers yielded by the validation criteria. There will NEVER be a perfect ("1.0") correlation between the test and the validation criterion, just as there is never a perfect correlation between IQ scores on one occasion and IQ scores on another occasion on the same brand of IQ test by the same group of test-takers.

There is enough play in the joints in both IQ test scoring (whatever the brand of test) and ranking people by other validation criteria (whatever they are), that strictly speaking one can't say that there is any all-time, universally significant ranking of human beings by intelligence. But a close-enough-for-government-work validation study would show an IQ test having correlations above .80, and perhaps even above .90, in comparison with previous brands of IQ tests, or in comparison with subsets of its own item content, or in comparison with some well regarded external validation criterion.

For reasons mentioned in another comment in this thread (above?), there is especially little reliability, and hence especially little validity, for IQ scores far above the population mean, and thus it's very hard to devise a validation criterion that would sort, say, members of Mensa

http://www.mensa.org/

or members of the Study of Exceptional Talent

http://cty.jhu.edu/set/index.html

or members of the Davidson Young Scholars program

http://www.davidsongifted.org/youngscholars/

into their "true" rank order by IQ, not to mention that IQ scores for the same individual can and do change over the course of life.

Interesting. Makes complete sense, but I never knew it was done that way. Do you know if there are any publically available raw datasets to play with?

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