Gifted Issues Discussion homepage Forums Identification, Testing & Assessment WISC-IV question about FSIQ and GAI

can you explain more about dumont-willis... our tester used them as well and I dont get it

thanks

These are the subtest scores

Block design 19
Similarities 15
Digit span 12
Picture concepts 13
Coding 13
Vocabulary 14
Letter number seq 13
Matrix reasoning 18
Comprehension 15
Symbol search 15

I think you are correct, I think the scores are transposed. We've asked the psychologist about this but he said they were correct, how can I present it to him so he makes the correction?

Thank you!

Composite scores
VCI 128
PRI 141
WMI 113
PSI 122

I would like to get the results corrected so we can bring it to the school and move forward from there.

Thanks again!

Hmm. Are the numbers you sent previously actually what he called the Index scores? Is there a table titled "Composite Score Differences"? If there is, it will have the four index scores listed again. The index score part really throws me wrt the psych's insistence that the scores are correct. Maybe you could start by asking him about the index scores, because those are patently incorrect (an index score of 25 would be at the lowest extreme of ability--like 24-hour nursing home care level).

As to the actual subtest performance of your ds:

He did extremely well on the PRI subtests, and borders on being a candidate for extended norms (max scaled score on Block Design). I would say he is probably skewed toward nonverbal intelligence, as, not only are his PRI subtest mostly higher than his VCI subtest, but the lowest PRI subtest, picture concepts, can be a mixed measure in many kids. I would not be surprised that a future re-test, on the WAIS, finds his PRI rising, when picture concepts is replaced. His working memory, honestly, does not look horrifically low to me, especially if the digit span is the result of significantly disparate DSF and DSB. I would look more to his day-to-day presentation to see if you and his teachers observe actual behaviors consistent with attending, remembering, and following directions. Also depends on just how low the DSF was. I don't know if you have that data, buried somewhere in the narrative or the back pages of tables. His processing speed is also not inappropriate for a gifted, deliberate/conscientious worker, clearly falling in at least the top of the High Average range.

I am not a psychologist so I do not have access to tables, but I have computed his scores to be the following:

VCI: 128
PRI: 141
WMI: 113
PSI: 122
GAI: 143
CPI: 123
FSIQ: 135

In that light, your son's profile is not at all atypical among gifted children. He true IQ undoubtedly places him in the moderately gifted range, with exceptional visual-spatial and fluid reasoning abilities, and strong verbal skills. His processing speed and working memory abilities are less remarkable, as would be expected of a gifted child, but nonetheless well above the population mean.

EDIT: Aeh, I just saw your post; brilliant minds think alike!

These make much more sense!

I see why the psych brought up wm as a relative weakness, though, because it is a mild statistical weakness. And this confirms my expectation that he presents with a mild relative strength in perceptual reasoning.

Nice work, Frank!

The actual GAI is 142.
The Dumont-Willis-2 CPI is 121.

Not at work, so I don't have the FSIQ table, but Frank's calculation is qualitatively close enough.

aeh

There is a section called composite score difference, the results are listed VCI-PRI, VCI-WMI and so on, however there are 6 scores not 4.

This is what was written regarding the WMI and DSF/DSB

The largest discrepancy between scores (28 points) was between his Perceptual Reasoning Index and his Working Memory Index. A difference of this magnitude is statistically significant and rare, as it is found in less than 4% of the standardization sample

He performed at an average level when number series were presented forward (five digits; 50th percentile), but exhibited above average skills when he was asked to recite them backwards (four digits; 91st percentile)


Should I have him correct the narrative as well as the scoring? He's been very resistant to any of our questions about the scores so I'm trying to put together the appropriate data to give him.

*I had found the date table from the WISC online and mentioned to him that I found ds GAI to be 142 not 135 but he told me I was incorrect. I'm glad to see that while I may not be gifted I can at least read a data table correctly :-)

The Dumont-Willis tables (they are freely available on the internet, btw: http://alpha.fdu.edu/psychology/WISCIV_DWI.htm) are conceptually the same as the GAI (for the DW-index-1), and the CPI (for the DW-index-2), but, not having access to the actual WISC-IV standardization data, they used mathematical manipulations of published statistical info to generate them. That's why I use the actual WISC-IV GAI tables instead of the DW-1. There aren't easily accessible WISC-IV CPI tables (although there will be on the eagerly-awaited WISC-V), so, if I want that info, I turn to the DW-2. The discussion upthread about GAI and CPI applies in its entirety to the Dumont-Willis indices. (Frank and myself both posted contributions.)

I know testing for giftedness can be very expensive and the fact that you received an incorrect score and little to no explanation of your child's performance strikes me as rather repugnant.

About your son's performance on digit span: forward digit span only has a g-loading of about 0.30, while reverse digit-span has a g-loading of about 0.40. This difference of 0.1 seems rather small, but in fact 77% more g enters into the reverse digit-span task than it does in the forward digit-span task. Thus, your son's much superior performance on reverse digit-span is to be expected. Moreover, there are many gifted children whose performance on forward digit span scarcely exceeds the population mean, and a number of them even perform in the below average range on this task. Thus, your son's performance is nothing to worry about.