I have three children, one has had five IQ tests, one has had three and the youngest two. Always triggered by school requests or pre-empting school requests (ie knowing we would change schools and the new school would want fresher "proof"). Schools here don't seem to consider results to be "stable" at any age and we have regularly been asked for testing less than 2yrs old, especially with regard to 2E provisions.
My kids look very gifted prior to school, generally have a shocking time during primary school (and schools clearly disbelieve giftedness), then do steadily better from 9/10yrs old onwards particularly in later secondary. From the testing data I have available this also tends to be borne out on their educational assessments: very high (mostly DYS) results around 5yrs old, often notably lower (but still gifted) results at 8/9years old, looking better at 12+...
Twice we used the same gifted specialist (the eldest children saw her twice, the youngest once). When we came back to re-test she was quite adamant it was pointless to retest, as scores remain stable or go down because of poor academic fit. I had friends who had gone through this same situation with the same psychologist, and gone ahead based on school insistence, resulting in a literally identical FSIQ, but tiny shifts within subtests. So I knew she was backing up her advice not to test with experience, she did not want to test, but school insisted.
One child had scores drop quite significantly and was described in the report as a completely different child, still polite, but difficult to test, disengaged, reluctant to cooperate or rise to any challenge. This was a child tested at approx 5 & then 8/9, and represented exactly what the psychologist had feared to see.
The second child had scores go up quite substantially between approximately 9 & 12yrs (10 points on FSIQ, despite their weak WM remaining completely stable, FSIQ moving from MG to solidly HG). The psychologist did attribute some of this increase to successful remediation of other Es but was also completely fascinated and talked to me at some length about how unusual it was to see a rise of that magnitude between ages of 9 & 12. That mostly you would only see scores decline or remain stable, given that it gets harder to score very highly as you get older. The psychologist suddenly became quite keen to test the middle child in another few years.
In addition to seeing shifts both up and down with the same tester on the same instrument we have also seen marked difference between SBV and Wechsler tests. So much so that I researched the research on this and did find an Australian article comparing the WPPSI and SBV and finding them to be very equivalent for the majority of children, with significant discrepancies for a small minority, with no clear pattern as to which test would be "better suited". They administered the tests in a mix of orders, with a variety of testers and in the children with big disparities between the two tests there was no apparent pattern as to which test had the higher result. From memory this included which test was administered first, a particular tester, same tester for both, different testers, etc. It just seemed to be the case that for some children one test or the other much better captured their strengths.
For my own children, in all of the subtests based on looking at cartoon like pictures all of my children did better on the SBV versions of those tests than the Wechsler versions, often substantially. All of my children had decent WM scores on the SBV and very average to appalling WM on the Wechsler test.... The child who has done 5 tests sits stably around the 12th percentile for WM on Wechsler tests and 87th on the SBV both times.
The youngest child has been tested with the SBV and WISCV. First the SBV at 4.5yrs old: high and even profile on the SBV (DYS level FSIQ). Then the WISCV at 9yrs old: exceptionally uneven profile, VIQ requiring extended norms, and up to 72points of internal spread between indexes. Verbal WIAT scores also in the DYS range and all other achievement scores in or near the gifted range.
In the end I have concluded that the WISC is very useful in proving their disabilities and the SBV far more useful in proving their gifts, but is no longer accepted here... And I would approach any future testing with no idea what to expect.
