Path: utzoo!mnetor!uunet!husc6!linus!philabs!ttidca!hollombe From: hollombe@ttidca.TTI.COM (The Polymath) Newsgroups: sci.psychology Subject: Re: Society for extremely gifted people Message-ID: <2079@ttidca.TTI.COM> Date: 11 Mar 88 23:32:57 GMT References: <7550@apple.Apple.Com> <3660001@otter.hple.hp.com> Reply-To: hollombe@ttidcb.tti.com (The Polymath) Organization: Citicorp/TTI, Santa Monica Lines: 48 In article <3660001@otter.hple.hp.com> gjh@otter.hple.hp.com (Graham Higgins) writes: >Some time ago the pseudo-science magazine "Omni" published a 4-sigma I.Q. >test designed by one of the leading lights of Mensa. ... I smell another IQ debate coming. Oh, well. I guess this group's more appropriate than most. Anyway, I didn't know that test was designed by a Mensan (or that Mensa had any "leading lights" (-: ). Live and learn. >... The "4-sigma" tag to >the test reflected the designer's belief that successful attempts at the >test could only be made by people whose I.Q. was at least 4 standard >deviation intervals above the mean ... Real tests are carefully normed against a sample of the general population, usually statistically sampled by census tract to insure proper representation. Belief has nothing to do with it. I don't know whether or not this test was properly normed. It costs a _lot_ of money to do it right. >... - I cannot be bothered to work out right >now what that is supposed to map out to (160/170+, I think). ... Before we start wrangling, let's clear up this misconception. The value of a standard deviation is totally dependent on the scoring method of the test. For the WAIS it's 15. For the Stanford-Binet it's 16. For the SAT it's 100 (with mean 500). Other tests have other sigmas. This means any reference to an "IQ" score is meaningless unless you know the mean and standard deviation of the scores for the test in question. What's important, and nominally constant across tests, is the general population percentile rank represented by the test score. Four standard deviations represents, approximately, the 99.9997th %ile (I think. My stats books are at home). That's a 160 on the WAIS, a 164 on the S-B and impossible on the SAT (which only goes up to 800). For reference, Mensa's admission requirement is the 98th %ile, Intertel requires the 99th, Triple-nine requires the 99.9th (of course), as does, I believe, the Cincinnatus Society. There are a number of other "high IQ" organizations with various requirements among them. Your mileage may vary. Now, let the flames begin! (-:{ -- The Polymath (aka: Jerry Hollombe, hollombe@TTI.COM) Illegitimati Nil Citicorp(+)TTI Carborundum 3100 Ocean Park Blvd. (213) 452-9191, x2483 Santa Monica, CA 90405 {csun|philabs|psivax|trwrb}!ttidca!hollombe