Your wrote about tests a few weeks ago, and I remember reading it. Maybe you can help us clear up why our son did less than average on the SSAT’s. He has a wonderful school record and is now in a private school even though his scores on this test did not match his grades in elementary school.
The SSAT’s are a secondary school test used to evaluate the academic competence of students usually applying to private schools.
You are not alone in your surprise and concern over your son’s scores. Candidly, I think grades are the best predictors and do not make too much of the SSAT’s.
Statistically, the scores on the SSAT’s are usually not especially informative one way or another, at least in my opinion.
The reason lies in the curve. Think about it. We are all on a curve for everything from height, weight, or excellence in math and English. If we could measure everyone, the curve would be spread out with many at the center and others falling into the top and bottom categories.
The population or sample of kids who take the SSAT’s results in a very steep curve. The students tend to have self-selected because they are competing for places at private schools. Therefore, the curve is tight. Everyone is close to the center or the “mean.” Just a few points make a huge difference because the population is so similar.
I wish I could draw the curves for you, but close your eyes and try to visualize the difference. The curve for the SSAT’s is described statistically as leptokurtic. That just means a steep, high curve. Now that you are confused, just put the test scores away in a drawer. Your son is more than a number.
Dr. Larry Larsen is an Andover psychologist. If you would like to ask a question, or respond to one, you can e-mail Dr. Larsen at lrryllrsn@CS.com.