N, there are two kinds of ceilings being mildly conflated here. There are ceiling rules, which are essentially as you describe at the beginning of your post, and have to do with rules of test administration, and there are test ceilings, which have to do with the limits of the normative sample. A gifted child is more likely than others to -fail to ceiling- as far as test administration, by not receiving the necessary number of zero responses to trigger the discontinue rule before reaching the end of the subtest. Jefferson appears to be inquiring about reaching a test ceiling, which is a situation where the test/norms are insufficiently high level to capture the full range of an individual's ability. This is the situation for which the extended norms become relevant.
aeh, I am trying to understand DD11's recent WISC scores (for which we don't have the final report yet). Apparently she did not reach the discontinue criterion on two or three different subtests, and yet she only got one 18 scaled score. Does this make sense? How can you run out of test without maxing out the score - especially when the test goes up to age 16 and you're only 11? Shouldn't the test have enough range that this can't happen?
