Ratio IQ estimation versus IQ tests

It occurs to me that ratio IQ estimation has a great advantage over IQ tests. All IQ tests have ceiling effects: a gifted child can easily bump against these ceilings or have their test score lowered without even bumping against them. The simple presence of a ceiling has a depressant effect on scoring.

So what can we do about this? Well, I would advise an older method of estimating IQ, used for assessing the IQs of people who were not able to be tested in any other ways: ratio IQ estimation.

Why is there an advantage to ratio IQ estimation, as detailed in the previous post? Well, there are NO ceiling effects and you are getting a true grasp of how gifted a child is. The estimate of IQ obtained by looking at ratio IQs may seem a rough guide - but it could prove far more accurate than measuring the more gifted children with a test that has a ceiling of some kind - even a high ceiling. The estimate you get will not have been capped by the ceiling of a test. In this way, we can be sure that the estimates of historic personages like William James Sidis - estimated at 250 to 300 - are accurate, in the sense that they are likely to be at least a threshold below which he could not have been, to have achieved what he did.

So, are we to throw away IQ tests? Well, perhaps for our most gifted, we should - because ALL IQ tests have natural ceilings and all will depress scores for the most gifted. This problem is now much more serious than it used to be, since, for reasons that are quite unfathomable, all modern tests are designed to lower the scores of gifted students. All of these tests will give an inaccurate assessment of any gifted child.

So, if you want a truer handle on your child's giftedness, calculate a ratio IQ: it will give a better insight into the true state of affairs, if your child is one of those who hits ceilings.