Nonlinear Psychometric Thresholds for Physics and Mathematics

coase
Mon, 02 Jan 2012 08:02:41 +0000

I am late to this discussion but I have to point out a glaring inaccuracy on the first page. calmom stated:

Physic and “pure” mathematics were the ONLY areas where there seemed to be a consistent correlation between SAT scores and achievement. This suggests to me that colleges would do well to dispense with the SAT entirely except for math & physics majors – or certainly to reduce reliance on the SAT for other majors.

&lt;/p&gt;

In fact, what the authors actualy stated was the following:

Interestingly, no similar threshold exists in other majors, such as Sociology, History, English or Biology, whether on SAT combined, SAT-R or SAT-M.

That is, they only say there is “no similar threshold.” Indeed, they go on to say this:

Despite the somewhat higher correlations, we discovered impressive cases of high achievement by students with relatively low SAT scores: in almost all majors (e.g., English, History, Sociology, Biology, etc.) students with combined (math + reading) scores well below 1000 (i.e., below the average among all SAT-takers) achieved in-major, upper division GPAs (henceforth, upper GPAs) in excess of 3.5 and even 4.0

So, yes, some low-SAT students do well in other fields, but there are actually “somewhat higher correlations” in those other fields.

The authors also refer to their earlier paper [Data Mining the University: College GPA Predictions from SAT Scores by Stephen Hsu, James Schombert :: SSRN](http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1589792). In it, they directly address the predictive power of SAT scores:

In addition to our primary result, we find that the best predictor of GPA is a roughly equally weighted sum of SAT and high school GPA, measured in standard deviation units.


There goes the argument for dispensing with the SAT entirely.

Finally, it is humorous to see the vehemence with which people argue that high school GPA is the best predictor of college GPA. (Next you will tell us that SAT math scores are the best predictors of GRE math scores. That is not much of a revelation.) It is a little like saying that today’s high temperature is the best single predictor of tomorrow’s high tremperature. While true, using that single instrument exclusively causes you to miss the events we care most about–the big changes in temperature.