I am less concerned about the WIST scores. They suggest that decoding skills have normalized, which is consistent with the other achievement data. The related areas with lingering mild delays are in reading fluency and spelling, with spelling results somewhat variable across instruments. And letter sounds on the WIST is a bit harder than on some other measures because if you don't name every sound that a specific consonant can make (even though you can read it in real words), you don't get full credit. E.g., how many adults can name all the sounds of "o" off the top of their heads?
On the WJCog:
The standard global measure for the WJ (analogous to the WISC FSIQ) is the GIA. The reasoning measure without speed and working memory (analogous to the GAI on the WISC) is the Gf-Gc.
Yes, the differences are 34 and and 55 SS respectively, which are +2 and +3 (nearly 4) SD. But this really just references fine-motor speed, which hypothetically can be accommodated with extended time and typed response. Not saying it isn't a real deficit, but that district and state regs vary on how this would be supported. I'm less concerned with this processing speed weakness per se, and would pay more attention to the quality of response on extended writing (both spelling and story composition).
