It sounds like your ds had the WJ-III Cognitive Abilities test from the names of the subtests you mentioned. My ds has had both the WISC and the WJ-III Cog, so here's what we saw that pointed to dysgraphia in each:

WISC - Processing Speed score (combined score), Coding was low (around an 8, median is 10, all other subtest scores for ds were way high).

WJ-III - Most scores were really really high, some were scattered around but still high, and visual matching was down around 34th percentile.

I don't remember the specifics of the visual matching subtest, but I believe it's the test on the WJ-III that most closely correlates with the coding subtest on the WISC. The coding subtest is timed, and requires the child to copy symbols that have a directional component to them. It's not an easy task for a dysgraphic child. I don't know that it would be an issue for a dyslexic person - my dd who has a dyslexia diagnosis actually gets a relatively high score on this type of test.

If I have time later today I'll pull out my ds' WJ-III test scores and see what his scores were for rapid picture naming and decision speed.

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The diagnosed him as dyslexic based on large discrepency between IQ and reading performance, decoding, spelling etc.

Reading performance is measured from the achievement tests not the cognitive tests (IQ is derived from the cognitive WJ-III). There are typically additional reading-skill-specific tests for decoding, spelling etc in a dyslexia screening.

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How do they test for ADD? Is processing speed part of it?

My understanding (and 2 of my kids have been screened for ADHD, my ds has been screened three times), is that a low processing speed score isn't used to diagnose ADHD, but it is often lower than other subtest scores in children who have ADHD. However, it can be lower for many other reasons too.

I am sorry I can't remember back to the beginning of this thread - but did your dd have private testing when she was diagnosed with dyslexia or school testing? If she hasn't had a private neuropsych eval, it might be really helpful to pursue one.

Best wishes,

polarbear