I've heard many mixed reports on the accuracy of the CogAT. On the other hand, our district uses the NNAT and I've talked to dozens of people who's kids have tested with that. It's obviously not a perfect test either (can miss GT kids too, especially verbal kids, kids who test young may have inconsistent results, etc). Anecdotally however, the dozen kids or so kids I know that have gotten above a 99 PR on the NNAT have all present as quite gifted 4 years later with consistent IQ and/or achievement scores (even those that weren't necessarily showing it at age 5 or 6). And in most cases globally. If you feel like you need more info, you may want more testing. I'm also surprised your district doesn't ID him with the MAP and NNAT scores that he has.
