Gifted Issues Discussion homepage Forums Identification, Testing & Assessment WISC IV subtest HUGE variation/discrepency

DS was tested with WPSSI at 5, FSIQ of 142. We've had him retested now at 9, with the WISC IV and the FSIQ has gone down to 135. I have no idea if 7 pts is considered "significant," and if so, what it means.

Also - the subtests on the Perceptual Section varied so much it was jarring. Block Design and Picture Concepts were both 11 (63%tile), while Matrix was 16 (98%tile).

Verbal - 142; Perceptual 117; Working Memory 138, Processing Speed 115. That's a 27 point spread - which I'm SURE must be significant... right? or no?

My question is, when we have a follow-up conference call to discuss these results, what do I need to ask? Are we talking about a 2E kid here? We have never seen a test with this degree of variation, but I guess it would explain some things...

Anyone have any experience with this?

Someone else recently had a post like that, with a gap between verbal and perceptual. That might give you more info. We had a gap the other way around with verbal being 27 points lower than perceptual. The neuropsych didn't seem too concerned about it. He was also tested when he was 3.5 on one of the weschler preschool versions and his nonverbal/verbal composite went up from 106 to 133. So there can be fluctuations over time as a child ages, either because their brain matures, or because they didn't do their best on the lower scoring test and the result wasn't accurate. Studies show that IQ is not really stable until mid to late elementary school.

There are tons of posts on here with that kind of scatter or more. We had a 55 point gap but decided not to worry about it.

Why did you have him retested? Was there some concern?

You may get the answers you need after talking to tester. As for the spread between VCI and PRI, there was a spread between our ds's as well. It didn't concern the tester.
And regarding the lower score, I've read that it's both harder for an older child to score higher on the WISC and that it's harder to score as high on the WISC IV than it was on the WISC III. For instance, the kids who scored 130 on the WISC III were scoring 125 on the WISC IV. I'll find the link with that info when I'm not on a mobile.

I'd ask the tester what their impressions are re whether or not your ds was engaged or was he distracted during the testing, what order were the subtests given in, and their thoughts re what might cause the scatter in the scores. As another poster mentioned above, the tester may bring this up anyway. You can also ask the tester to explain how each subtest is administered (oral questions vs reading etc), how the response is given (oral vs written) and is the subtest timed. With some types of 2e, there will be a pattern in the range of scores based on this type of info.

I am also curious re why you sought out this second set of testing? Was there a concern? Has he had any type of struggles at school? If the reason for testing was some type of concern... then the tester will most likely address that issue in your follow-up interview and let you know if any of the score scatter relates to it. If you let us know what the concern was, it's possible that there are 2e parents here on this forum who have similar situations and challenges who might be able to give you help with understanding the scores.

Last thing I'd recommend - do you have the subtest scores from your ds' WPPSI? My guess is that his FSIQ from the WISC-IV is very similar to the range he received on the WPPSI - they seem like different #s but they aren't terribly far apart, and as another person mentioned above, the scores coming in on WISC-IV seem lower in general than previous the previous WISC. If you compare subtest scores, look to see if you see the same pattern in score fluctuation across subtests (the subtests aren't going to be exactly the same, but they will test similar skills). If you see the same pattern, it's most likely telling you something that's "real" about your ds - but whether or not it's anything to be concerned about depends on what's happening in real life - is he doing ok, or is he having trouble at school? Or do you or his teachers feel he seems to be underachieving?

Best wishes,

polarbear

Oops. I didn't catch that the first test was the WPPSI.

We had him retested to attempt to get into Davidson - his 142 score was 3 yrs ago, and they wanted a more recent score. Now I'm reading that WISC-IV rarely gives scores in the 140's. I'm not concerned I guess so much with the score itself, the more I think about it - I'm more concerned that it went down so significantly in the PRI - more than a whole standard deviation.

I'm finding more and more now that I look at the two tests - Two of his PRI subtests dropped from 16 to 11... nearly 2 standard deviations.

And because people asked, we had him retested for admission to Davidson Young Scholars. The last test was too old. We were hoping some Davidson programs could supplement his regular school - But now I'm reading that WISC IV rarely scores in the 140's or higher, so I guess not.

I'll probably just forget it. We'll just enrich him as much as we can at home. Not much else we can do.

I do stats for a living, so I know anything that's nearly 2 full standard deviations apart is odd. That means one of the two tests is an outlier... and the only way to tell which one is to take ANOTHER test... for hundreds more dollars - - no thanks.

The more recent score is probably the accurate one, unless you have some reason to believe he didn't do his best on the test. IQ testing is very unreliable in younger kids. Some will have inflated scores if they were exposed to lots of things at home (books, vocabulary, puzzles, educational toys, etc that other kids may not get) and others will have scores that are underestimates if they are in an unstimulating environment or they had developmental delays, a developmental disability, stranger anxiety, etc. Some kids simply develop faster than others. So the baby that walks at 8 months may not end up being the athlete in the long run. My DS has speech and motor delays due to being dyspraxic so it's really hard to get an accurate result on IQ tests even at age 6. As he matures his scores keep rising. I think a 140 on the WISC is around 99.5 percentile so one out of 200 people?
Hope this helps.