Anonymous wrote:When comparing the NMSF numbers for TJ or Blair to the top independent schools, also worth remembering that TJ and Blair use testing as the single biggest factor to determine admission from 8th grade, every kid in those schools was specifically selected for doing well on multiple choice tests just two years before they then take the PSATs. Sidwell, GDS, Cathedral schools admit kids as early as PK for Sidwell/GDS, 4rth grade for Cathedral schools, and while SSAT and IQ testing is used, not as the only factor, and early performance on these tests may not predict later performance on PSATs or SATs. Also huge sibling preference at these schools, not to mention all the other preferences people worry about. For the kids that enter Sidwell/GDS/Cathedral schools for high school where they have been tested more recently and those test results matter a lot for getting in, suspect the percentage of NMSF much higher than the overall school population that includes "lifers."
I totally agree with these points.
Trying to compare PSAT or even SAT scores between a K-12 school and a 9-12 school is very problematic, especially when the 9-12 school admits largely on the basis of SAT-like tests. It's sort of like telling two high school coaches that they will face off in a to-the-death soccer match, and letting each coach pick her team's players. But one coach gets to pick all her players at tryouts held just one year before the final match. The other coach must pick half her players several years earlier, when they are only 4-8 years old, and just hope they can be molded into top athletes over the next 8-10 years of training. That's not to take anything away from a school like Blair -- it clearly has incredibly smart students. It just makes an apples-to-apples comparison very hard. By comparison, it's a decent point of comparison between two schools with fairly similar profiles, such as StA compared to NCS.
A very interesting analysis would be to look at lists of "lifers" from several schools, and see what percentage of the lifers end up being NMSFs. Is the lifer percentage higher, lower, or about the same as the all-student percentage? If anyone can post links to lists of lifers, or will just PM me some lists, I'd be willing to do the math for comparison.
Sam2