Here is my reading of what is there and only pertains to the SCAT.
Norms on the 'next day' results are from the full(er) population of 8th graders which spans the entire Gaussian distribution curve in terms of ability.
The prior test date results are normed against test takers supposedly in the top 5% where grade < 7. Understandably but somewhat counter intuitively, until you take the LOG of some of the early test takers into account, the percentiles ranking can actually slip down when measured against early taking grade peers.
Also, the tests vary in difficulty/different cohorts vary in ability as measured against a particular edition of the test - the percentiles 'wobble' a bit between sittings.
I do not know when the final 2015 grade normed percentiles will be released but I am expecting my DD10s percentiles to go down when that happens relative to the full 8th grade ones.
Make better sense or have I made it worse? LOL
Last edited by madeinuk; 03/17/15 06:33 AM. Reason: Removed some ambiguity
