Gifted Issues Discussion homepage Forums Identification, Testing & Assessment How does a GAI drop 20 pts?

My son scored above DYS level in his IQ testing 3 years ago. He was just retested and his GAI dropped by 20 pts putting him below DYS level. How the heck does that happen? Tester did say that he does have multiple LDs. But, is he no longer PG?

How old was he when he was first tested? The scores of really young kids are not reliable and can change a lot (under age 6 or 7, if not later).

He was 8 for the first test. Since that first test, we made accommodations at school with multiple grade skips in subject areas. It has all worked well. He has been able to perform as a PG student at the appropriate levels, in certain subjects, so it comes as a surprise that there could be such a drop. However, he has been struggling a lot in other areas so the LD is not a surprise. Also looking at my notes, the tester used a newish test. Wisc v. Does that make a difference?

I was wondering the same thing as blackcat - how old is he now and how old was he when first tested? I would also look at his 2e issues, and try to make sense of how they are impacting his test scores, as well as look at the tests administered both times. Was he tested with the same test? I'm also wondering... did you see indications of his LD when tested the first time? I'm guessing you did since you mention GAI and not FSIQ. Is it possible that the impact of the LDs on test results is more significant now than it was three years ago?

I have a dd who's GAI dropped significantly between testing at 5 and testing again at 8. In her case, she had a significant drop in subtests that were tied to vision (and was then diagnosed with a visual challenge), but she also had an overall general drop in scores. She was tested with the WPPSI at 5, and the WISC at 8. I believe that the later WISC scores are more accurate in her case, because they reflect more of what we see in academic performance and also what we see in standardized testing.

polarbear

No, different test. Wisc iv and then wisc v. The reason why we went for the second round of testing is because we have seen a dramatic drop in performance in certain subjects. So yes it's possible that LD is having a greater effect.

I like the WISC-V better than the WISC-IV, actually, and generally find that it is better for 2e kids. There are, however, several factors that I can think of off the top of my head, not including the possible long-term score depression effects of unremediated disability.

1. Norm obsolescence: He was tested very late in the norm age of the WISC-IV, and quite early in the norm age of the WISC-V. That is good for a drop of 3 points for average cognition kiddos, and quite possibly more for children in the upper extremes (where the Flynn effect appears to be more pronounced, and less predictable).
2. GAI factor weighting: The WISC-IV GAI is roughly one-half verbal, one-sixth visual-spatial, and one-third fluid reasoning. The WISC-V GAI is two-fifths verbal, one-fifth visual-spatial, and two-fifths fluid reasoning. A child who is strongly verbal, but not as exceptional in fluid reasoning, may experience a drop in GAI, as his area of strength is a slightly smaller contributor, and his area of relative weakness is a bigger contributor.
3. Developmental trajectory: the level of abstraction required for scoring far to the right on the curve increases steeply after latency age (around age ten or so, entering the tweener years), as the population shifts toward abstract thinking. If one is ahead by the same (hypothetical) absolute amount in abstract thinking at age 11 as one was at age 8, it's a smaller distance to the mean at age 11, because hardly any 8 year-olds had abstraction, but a great many 11 yos, do, at some level. In addition, LD kids not uncommonly have unusual challenges at certain developmental transitions.

Still looking at my notes, tester said his FSIQ dropped 10 points. But she noted that he is "still PG and should be in appropriately placed classes". I guess I'm confused. How can he be PG if he no longer makes the DYS cutoff? I'm just concerned about educational placement and his sense of himself. At some point, soon, he will ask about his results and then will make a big fuss about not belonging in Davidson anymore and not being in the "right" classes. I'm looking for how to explain this to him and I don't understand it myself!

Another way of thinking about this is to remember that IQs, though we tend to think of them in absolute terms, are only approximations of the true ability of an individual, affected by many small moment-to-moment, day-to-day factors that we collect under the descriptor of standard error. This is why they are most appropriately reported in ranges (formally called confidence intervals). Typically, index-level scores (FSIQ, GAI, VCI, VSI, FRI, etc.) are reported with 95% confidence intervals, which, for the WISC-V GAI, spans about 9 or 10 points (similar for the other WISC-IV and -V index scores). This is why a 10 point drop in FSIQ is not a huge deal, especially when moving from one edition of a test to the next. The 20 point drop in GAI is a bit bigger than might be expected based purely on standard error, but not completely unreasonable taken in combination with the factors I listed previously.

Secondly, it is worth considering the arbitrary nature of the definition of PG. Falling slightly below an artificially-determined cutoff doesn't mean this intellect is qualitatively different from one measured at two points higher. (And again, remember that the confidence interval may very well stretch to above the line, anyway.) If we choose to classify intelligence, which appears to occur on a continuum, we have to draw lines somewhere, not necessarily for intrinsic reasons.

Finally, psychometric reasons for score variations aside, why does it matter if he is MG, HG, EG, or PG? Will it make a difference in placing him appropriately, more so than his demonstrated academic needs (based on performance, intellectual satisfaction/challenge, balanced development)? Would you pull him out of his current classes if he were successful and happy in them, just because his number had fallen a little? Conversely, would you push him to be stay in classes where he was clearly floundering and stressed, just because his number said he "should" be able to perform at that level?

At the most simplistic level, does Davidson kick kids out if their scores fall? I doubt it.

Ugh I suspect that this is going to really affect my 2e kiddo… he was tested a year and a half ago on the WISC IV and his GAI was HG but his 2e brought his FSIQ down to MG. The school district has finally agreed to retest him based on his diagnosis but now I am worried that the Flynn effect plus the change in weight of subtests will wreak havoc with my verbally strong kiddo… he was 99.99% for VCI but only 98% on the PSI for the WISC IV… now the new test is weighted against him AND he will score lower for his GAI. We have tried to get his 2nd e sorted out, but I still have no idea how he will test…..if his GAI goes down 20 points it will be a major problem as the school that I think he would do well in is for HG kids only.

98%ile on the PRI, I think?

LAF, I wouldn't worry prematurely about GAI drops on the WISC-V, for your DS. His lowest PRI subtest on the WISC-IV was actually the subtest that did not make it into the WISC-V. The VSI also now includes a motor-free spatial reasoning task. He did pretty well on the one fluid reasoning measure that is retained on the WISC-V. So it is possible that his GAI may not be adversely affected by norm obsolescence, especially now that motor considerations affect only one-seventh of the GAI (I recall that coding/fine-motor speed was his lowest score), and abstract reasoning is better represented (with the addition of a quantitative reasoning measure).