Gifted Issues Discussion homepage Forums Identification, Testing & Assessment WISC-IV, GAI question and subtest scatter?

DS9 recently took the WISC IV as part of the entrance criteria for our local G/T program. Their decision is still pending, but I had some questions that the school psychologist who administered the test seems unable to answer fully. Hopefully someone here can help?

First, the difference between VCI and WMI is 37 points. Does that render the FSIQ uninterpretable? Is this a case for the use of the GAI? The GAI I calculated from the subtest scores is 8 points higher than the FSIQ so I think it is worth mentioning in the psychologist's report, but the school admin. is resistant for some reason. Not sure if I should be lobbying harder for its inclusion or is it insignificant?

I was also surprised by a PRI score of 123, which I thought seemed low as math is DS's favorite subject at school and he completes work at least 2 grade levels above his current year. Subtests scores are as follows, I think this qualifies as scatter? BD 12 , PC 12, MR 19. It seems unusual to me that MR is in the highly superior range and the others are just average. I would think a math strong kid would have scores clustered closer together? All subtests on the other indices were within one point of each other, so I can't help but think something is going on with that PRI score. Previous standardized test have put him in the 99% for nonverbal ability.

Any insights regarding the subtest scores and GAI issue would be greatly appreciated. Thank you.

I submitted this position paper about the WISC IV

http://www.nagc.org/sites/default/f...20WISC-IV%20for%20Gifted%20Education.pdf

And the testing/psych person for our district did enter DD's GAI. I think she would have qualified based on her FSIQ but the GAI was 15 points higher and gave her a stronger case for needing to be in a certain program. Now that guy is gone and they claim they will accept FSIQ results...no one understands the WISC. We used outside scores and normally they use the CogAT.

In terms of the PRI score, DS had a scatter with 19, 18, and 13 (block design being lowest) and in his case I think he did worse on block design because it is timed and he has poor fine motor skills. I'm not sure what would bring down a PC score though compared to Matrix Reasoning. My kids both had similar scores on those two subtests (18-19 with block design being lower, 13 for DS and 16 for DD). Did he do well on the processing speed subtests?

Thank you blackcat. I had read the position paper but had not considered submitting it in support of using the GAI. Were it not for the BD and PC subtests I wouldn't be as concerned. I am afraid those scores may red flag him as comparatively weak non-verbally when achievement wise that is just not the case.

Fine motor skills could definitely play a part with the BD subtest. DS has always been a bit weak in that area. Processing speed subtests were in the superior range so I don't think that is the issue. So the PC score is still a puzzle to me. Thanks again for responding.

In our case I think they just went ahead and entered the GAI because of the paper and it also said it in the report (that the GAI should be used because of discrepancies). DD was probably the only kid who had a WISC score. In your case, it sounds like they are giving the WISC IV to lots of kids? They probably don't want to calculate a GAI because then they would have to do it for everyone meaning more work. I would present it as something that SHOULD be done, though, for everyone who has a discrepancy between scores (and a GAI can be calculated), not just your DS. Of course, if his FSIQ qualifies him for services, then you wouldn't need to bother with any of that (unless you want to for the principle of the thing).

I think you hit the nail on the head, calculating the GAI for DS would equate to doing it for all who fit the profile. At this point, DS has a qualifying score for services but our district is quite competitive so not all kids who qualify will be offered services. I was thinking the GAI could possibly strengthen his case. But since looking closer at his subtests I think my bigger concern lays with the PRI scatter. Even if he qualifies for services I can't help but wonder if there is an LD or other issue going on there that was previously unnoticed. And its also quite possible I am overanalyzing the whole thing!

A 37 pt difference between VCI and WMI would certainly make the FSIQ suspect. Not uninterpretable, precisely, but to be viewed with significant caution. This may or may not be an appropriate situation for the GAI, partly because I believe you indicated that his PSI is substantially higher than his PRI. (Which is probably why the GAI is only 8 points higher than the FSIQ--significant, and rare enough in the general population, but not remarkable (20% base rate) in the GT population.) The best case for the GAI is when both VCI and PRI are high, and both WMI and PSI are low. Second to that would be VCI and PRI high, and one of WMI or PSI is somewhat high, and the other is much lower. I do lean toward using the GAI in the GT population, in most cases.

His PRI subtest scores suggest that he has exceptional abstract thinking skills (matrix reasoning), but only average concrete nonverbal skills, including perceptual-motor (block design). The latter may be affected, of course, by visual and fine-motor skills, in addition to actual visual-spatial problem-solving skills.

Math is about logic, patterns, and reasoning, which is also what matrix reasoning is about. Block design is primarily perceptual in nature. And it's timed, which is not good for those who like to sit and ponder deeply. Picture concepts is concrete, and relies to some extent on verbal concepts. So it is significant subtest scatter, but it's not that strange that a math-y kid would score exceptionally well on mr, the abstract task, but nothing special on bd and pc, the more concrete tasks.

Thanks for that insight aeh. Though I would have expected DS to score a bit better overall on PRI, I am now less concerned that the scatter has ominous undertones.

Regarding the GAI, the PRI and PSI were quite close actually, within a few points of each other, with PSI slightly higher. Would that make use of the GAI more or less appropriate in your opinion? I have to admit that your description of the FSIQ being "viewed with significant caution" makes me a bit nervous about how the G/T admins will view his results!

So if I'm understanding correctly, it sounds like the VCI was the highest, and then PRI and PSI were in the same area, slightly lower than VCI, while WMI was much lower than all of them.

That lends support to using the GAI, I would say, as the view would be that the WMI is artificially lowering the FSIQ.

I'm going to throw in another thought, which is that if, as I suspect from your description, the VCI is a good 10-15 points higher than the PRI and PSI, that would suggest that even the GAI is a low estimate of overall cognition. Not that I expect GT screeners to view it this way.

Not to scare you or anything, but, in the category of things to be/not be concerned about: just how low was the WMI? Was it both normatively (<90) and relatively (<

Your estimate of DS's testing profile is very close. The VCI is a bit higher than you noted, more in the neighborhood of 20 points. WMI was solidly average, so only low in a relative sense. I am curious now, why would a VCI gap with PRI/PSI suggest that GAI is a low estimate of cognition?

I am curious about this too.