NWEA themselves acknowledge MAP RIT scores in reading cap out around 245 even if the scale goes up to 300. I think I read on this site that MAP Math goes up to 320 and ceiling kicks in at 260.
"A ceiling effect exists when an assessment does not have sufficient range to accurately measure students at the highest performance levels. It has nothing to do with the actual numbers attached to the scale and everything to do with the position of students on it. For example, in reading, the RIT scale measures with relative accuracy up to about 245. This represents the 93rd percentile at grade 10, and the 95th percentile at grade 8."
https://legacysupport.nwea.org/support/article/532 Not sure what alternatives exist,
http://www.scholastic.com/education/assessment/literacy/sri-index.htm and they have one for math too.
EDIT: OK wait this may be the answer, the MAP 6+
https://docs.google.com/document/pub?id=1nA_PlvjvwFTi5vMwRxlfmmVUJo63pfwn67ZAMHaV4oUhttps://www.nwea.org/content/upload...ath-6-plus-Transition-Guidance-MAY15.pdfSo my question now is, does the "MAP 6+" still have a ceiling effect, and at what RIT score. I don't think NWEA is responsive to questions from parents, only from teachers.
