With children up to 16 or so, you’re dealing with ratios (of mental age to real age times 100) and with adults you’re dealing with prior statistics and comparing the results to that.

But unless there was a REAL (individually administered) test involved, you’d do best to stop thinking about it altogether!

The only difference as I understand it, is that a child usually learns more than an adult as they are always seeking information. The more you’re learning, the more ability you have to learn, therefore making your IQ score higher. The score is not what you know, but how much ability you have to learn. (That was the way it was explained to me.) I think of it as stretching your brain.

Second, even if you were to take a valid I.Q. test, the test you would be administered would be normed for your age range, so there would be no need to convert scores from one age range to another.