Gifted Issues Discussion homepage Forums Identification, Testing & Assessment New here/Ceiling Q's

sallymom - are qualified testers using them outside of these criteria, though? I imagine, statistically, they are seldom used. This list probably has a much higher than normal group of DC who would be eligible for the extended norms.

He seemed to indicate that they were but it was because the parameters were not listed appropriately by the publishers of the WISC-IV, not necessarily because anyone was knowingly using them incorrectly. He did use them for DD (she met criteria) and as you said I am sure there are many other children on this board who meet this criteria. But if there is, for instance a VCI or PRI that is 99.9 but the other score is 97 percentile then extended norms should not be used even if the GAI is high enough, I am guessing that is probably when they are most often used incorrectly. I am guessing the maxing out of at least one subtest is only important because without doing so someone would have been excluded from the norming sample. I am far from a statistician but it was very obvious the psychologist explaining this to us was.

With those kinds off cutoffs to qualify for extended norms, a single question could make a huge difference in score. That is not a robust system.

Really it would have been better if they'd tried harder to avoid ceiling effects in the first place.

The impression that I got from reading about it obsessively back when we first got DD's results is that the WISC was never intended as a tool for recognizing the gifted but rather as a tool for diagnosing issues at the other tail. Consequently, its ceilings are too low and things get too 'compressed' at the tip of the RHS tail.

This is the case--both psychs who saw DS gave him the WISC (or WPPSI back in preschool) for other reasons, not to figure out if he is gifted. The first time because he had odd delays, the second time because he still had odd delays, I noted that there had been discrepancies (huge gaps) on the WPPSI a few years earlier, and he had a brain injury. He likes using the working memory section to identify possible ADHD.
But the whole test needs to be done to find discrepancies.

My thought on it is that once you reach a certain point like 99.9th percentile, does it really matter about getting an exact number? It's not like someone is going to say "this person has an IQ of 200 vs. 160 so we will grade accelerate 4 years instead of 2 years." The same issues would be present in both cases. DD has a GAI >99.9th percentile--personally I'm surprised she tested that high in the first place, there are a lot of factors going into it (like her being super careful with her answers or maybe just luck on that day), it can change a lot over time, and I'm not going to get too hung up on what is her exact IQ....it just doesn't matter that much. I now have a general idea of where she stands and that the non-verbal questions come easier to her which is good info to have.

blackcat, I can't speak to why this particular examiner gave three wm subtests, but when I do it's often because a) there was a marked difference between the standard two wm subtests (ds and lns on the WISC, and ds and ar on the WAIS), b) I want to investigate rote memory vs memory with higher cognitive load (possibly because there were differences between digits forwards and digits reversed), or c) one of ds or lns was spoiled or suspect (in which case that scaled score should not have been reported at all, or with an asterisk). Some examiners cling to the outdated AC(I)D profile, which was once thought to be diagnostic of ADHD; that would require giving Arithmetic.

The score tables in the report should list which subtests were used in the composites. It might be in tiny print under the table of IQ/Index scores.

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.

I have inserted a link to Pearson's official extended norms, in case your examiner doesn't have them:

http://images.pearsonclinical.com/images/assets/WISC-IV/WISCIV_TechReport_7.pdf

As you will see from the TR, N is correct about the two-subtest criterion for using extended norms.

Jefferson, Coding is fine-motor heavy, which makes it a mixed measure of processing speed. Especially with younger high-ability students, I sometimes substitute Cancellation, which has fewer fine-motor demands.

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?

My DS got a 15 while not reaching the discontinue criterion (that is, he reached the end of the question list). It can easily happen by getting several wrong answers, but not consecutively.

How bizarre. OK, thanks.

Can you clarify what you mean by this?