Dude that is interesting and I understand the mathematical reasoning for what you are saying. How would you tell a child who did well on the test because they are truly that gifted from a anomaly.
My guess is you don't other than observation, time, or additional testing?
My son has traits like the early speech, started reading at 2, learned all the states and capitols by four which includes by shape of state, plus can map most of the world and now it's the solar system he has switched to.
However he seems to jump around from interest to interest. It's not like he is reading Les Miserables or calculating super advanced math problems in his head. He just seems to really get stuff and master it after a very short time.
So I am curious the accuracy of a score like his.
I'd say with the scores you've reported, along with the personal observation, the question of whether or not he's gifted has been authoritatively answered. The RIAS does tend to correlate fairly well with other test scores, it's just that where it tends to err, it tends to err in the ways I've described. The tool is what it is, which is a quick way to assess children who may or may not be good candidates for intervention.
He hit the ceiling at 160+, but maybe the score was skewed a full standard deviation too high, and he's really in the 145 range. That's still in the Highly Gifted range, and that's probably the lowest-case scenario. The probability that the score was skewed more than 2 SDs too high, and he's below the 130 threshold commonly accepted as gifted, is ridiculously low.
The question now is, do you have the information you need? If you need access to DYS, and DYS doesn't accept the RIAS (I haven't checked), then a more thorough test tool would be called for. Further testing might also be called for if you have any reason to suspect a learning disability, or if you're just plain confused with his learning styles, which more specific testing can help identify.
In my case, my DD took the RIAS and scored a 135, which was right in line with my expectations. That would not make her DYS-eligible, but made her fully eligible for gifted services at her school, so no further testing is needed there. And since her brain works pretty much the same way mine does, I don't really need any new insights into that. We have no reason to suspect any LDs. So that's pretty much it for testing, we got all the info we needed.
