Originally Posted by MidwestDad
....Invitations are mailed in late April to the highest-scoring students in grades 4 to 8, usually those who score in the top 1% for ACT and SAT and the top 2% for EXPLORE.

From http://www.ctd.northwestern.edu/docs/ctd/StatSum2011.pdf
The numbers of test takers are:
4th Graders N=3227 3227*0.02=64 or 65
5th Graders N=4660 4660*0.02=92
6th Graders N=3477 3477*0.02=69

From http://www.ctd.northwestern.edu/docs/ctd/acscorecriteria2011.pdf
The numbers of invited test takers for 2011 are
4th Graders 29
5th Graders 43
6th Graders 38

So I think that they only invite about top 1% for Explore test takers.

Do you think that I am right?


yes I think you are right. I've wondered about that too. The actual scores the "invited" children got were well over 99% percentile and the number of participants/number invited is about 1%. (I would bet they don't realize the website says 2%.). In some cases it is less than 1% , I think 6th grade is a little more than 1%. I'd bet cutting it off at sum score of 96 resulted in too few students, and 95 resulted in a few too many (e.g. a little over 1% of students)...

Last edited by herenow; 04/21/11 06:58 PM.