SAT/ACT percentiles

[EKS]

Can someone explain this to me?

A person who scores at the 1st percentile on the SAT or ACT is probably not getting into any sort of selective college.  Then why is it that the score ranges for both the SAT and the ACT devote so much real estate to the 1st percentile and lower versus the 99th percentile and higher?  For the SAT, 1st percentile scores lie between 400 and 680 (29 out of 121 possible scores; 24%) versus the 99th percentile which are between 1510 and 1600 (10 out of 121 possible scores; 8%).  Likewise, for the ACT, scores of 1-11 (31%) are at the 1st percentile whereas scores of 34-36 are at the 99th percentile (8%).  

Shouldn't this be reversed?  Isn't the more relevant information at the upper end?

ETA:  For the SAT in 1984, 17% of the scores were in the top 1% whereas 6% of the scores were in the bottom 1%, so it was reversed back then.

Edited September 22, 2019 by EKS

[daijobu]

This is a good question.  Why so much resolution at the lower end of the scale?  

The only information I can add is that the SAT was renormalized in 1996, raising the average SAT score.  Now my old score from 1986 is laughably low in my dd's estimation, while at the time it was considered a respectable score.  

With everyone's score now inflated, those with the highest scores are "bunched up" on the high end of the scale.  

That's how I see things, but I wonder if that is the entire explanation?  

Edited September 22, 2019 by daijobu

[daijobu]

I also made this chart based on the scores in the above linked table:

I think you can interpret the slope to represent the granularity of the scoring.  The higher/steeper slope at the lower scores shows greater resolution of scores.  You can see an area of greater slope in the math scores between 650 - 750.

You can see that with the exception of a 250, 550, 600, 700, 750 on the SAT math, the 2 curves are above y=x, so the scores are inflated at those points.   At 700, the new math score is actually slightly lower.  

There's more info in this College-Board produced article, but it's too dense for me to read.  

 

Edited September 22, 2019 by daijobu

[daijobu]

There's an old NY Times article from 1994 on the topic:

Mr. Quin said they were making the change so students would have a better sense of what their scores mean. When the current scoring system was established in 1941, 500 was the average score for each test, the math and verbal. Those scores have been declining for nearly four decades. The average verbal score today is 424; the average math score, 478.

So the College Board officials have decided to "recenter" the scale, changing it so the average student will once again get scores of 500 on the verbal and math tests.

That means by answering the same number of questions correctly, typical students will get about 80 extra points on the verbal test and 20 on the math. For over half a century, a raw score of 35 on the verbal test of 78 questions has translated into a 430 score; now a raw score of 35 will mean a score of 510. For the raw score, students get one point for each correct answer; they lose a quarter-point for each wrong answer.

"This way a student will know if he gets a 510, he's a little above average. A 490's a little below average," Mr. Quin said.

...

In 1941, when the current norms were established for scoring the S.A.T., the world was a very different place. A small group of middle- and upper-class Americans attended college. Just 10,000 students took the S.A.T. in that year and 40 percent of them attended private high schools. Today, 1.2 million take the test, 82 percent of them from public schools. In 1941, fewer than 1 percent of the test takers were members of minorities and 40 percent were women; today, those numbers are 30 percent and 52 percent.

As colleges diversified in the 1960's, opening their doors to more poor and first-generation Americans, S.A.T. scores began a steady drop. By 1969, the average verbal score was 462; today, it is 424.