NWEA MAP:
Math 220/216/242
Reading 237/220/232(Winter retake)/228
language 229/232/226
SRI:1027/1228/1264
Assuming those are in chronological order and all with the same test, that looks like no growth or negative in reading/LA. That seems like a good starting point to say that something is wrong, or that the current situation is not serving him well.
Edit: Assuming I am reading the chart (linked above) correctly all of those spring scores are greater than the 99th percentile.
The school only started using the NWEA this year so I don't think they have done much as far as looking at the data collected. I think they are looking at how his scores have remained in the 99% and above range for the whole year so all is good. Maybe they are right but I am looking a couple of grades ahead and, except for his spring math score, his scores have been steadily declining.
Math 98.5/91/99 (3rd grade)
Math 91/70/97 (4th grade)
Reading 99/97/93 (4th grade)
language 98/97.5/92 (4th grade)
