in actual postal mail

Where do you see the MCPS percentage?

I think it's just that MCPS is just a high-achieving county!

My kid was 95% verbal, but only 82% MCPS.

OP here -- that's what I figured, thanks!

Percentile is calculated based on your performance as compared with others

The MCPS percentile only takes into account the students of the same age, in the same grade that took the test. Students had to be recommended to test or their parents requested testing-- but it was less than 50% of the 5th grade students in the county.

The national percentile takes into consideration the students nationally of the same age and in the same grade who took the test... many systems use the test with ALL students, so a much wider range of abilities.

MCPS percentile is based on the students who took the test, not all MCPS population.

I think MCPS, being the dc area, does skew higher. My child, currently in a CEs, got a non verbal score of 83 (national), 64% for MCPS. How do they test non verbal skills?

My DS didn't do as well in the Verbal section as the other sections of the CogAT, getting 79. In the letter I just received, it says his National percentile is 79% but the MCPS percentile is 28%. That seems an extreme difference. Is MCPS just brilliant, or is it because it was a self-selected test?