Hacker News Reader

Comment by pg | Hacker News Reader

Is it really true that SAT scores don't correlate with academic performance?

The real question is, how does "academic performance" correlate with actual proficiency? In AP Computer Science, probably not much. I'm taking the test soon (trying to skip the course and go on to fun stuff). At least half the review book is about the Java standard class library. Much of the remainder is Java syntax and semantics and the brain-damaged system that Java programmers call "good object-oriented design". Oh, and another thing: chapter 5 of the review book has a section called "The Software Development Life Cycle". The first subsection of that is titled "The Waterfall Model". After explaining the waterfall model, it proceeds to completely neglect the existence of any other software development model.

One of the most noticeable differences between A and AB is that in AB, you go into algorithms and big O notation in much more depth, and you do some work with implementations of binary trees and such. When they cut out AB, they are leaving what is essentially an AP Introduction to Java.

It's sad that this passes off as computer science. I'm taking the test so I can hopefully skip the course and move on to fun stuff that has APCS as a prerequisite. Fun stuff like AI. AI, the class where Python and Ruby are the default languages, and you get to use other things if you want, like Lisp.

(I found this out when I still didn't know much about Lisp, saw someone using it, and laughed at the stupid, old language with all the parentheses. The guy tried to explain that Lisp is a good language, but I wasn't convinced. Later I independently stumbled on some of PG's essays, and I was convinced.)

Well finger length correlates with better SAT scores. I propose that finger length measurement replace SAT testing.

http://www.livescience.com/health/070522_finger_sats.html

Although I myself did well on the SAT's, I too am hesitant to support the use of correlations like these in determining what students, or anyone deserves.

With regard to SATs and academic performance, the first google result:

"Findings indicated a very low correlation between SAT math scores and overall college math grades of six graduating classes at one university"

http://eric.ed.gov/ERICWebPortal/custom/portlets/recordDetai...

Finger length correlates with testosterone production, which correlates with different ratios of mathematical to verbal skills. So it would tell you whether to go to MIT or Yale, but not whether to go to Wash U or Forest Park Community College.

You may enjoy this anecdote, in which someone even more self-righteous about such things makes a fool of herself:

http://isteve.blogspot.com/2007/05/finger-length-and-sat-sco...

Unfortunately the College Board changed the information architecture scheme on their website a couple of years ago so the URLs from my class notes no longer resolve.

There is one study that shows there is a correlation between SAT score and college GPA, but only for students whose HS GPA is above a 4.0. In general though the test doesn't really have any validity.

Here is a link to the studies the College Board is promoting:

http://professionals.collegeboard.com/data-reports-research/...

EDIT: http://www.fairtest.org/facts/satvalidity.html

"Various studies conducted over the lifetime of the SAT show a statistically significant increase in correlation of high school grades and freshman grades when the SAT is factored in." from wikipedia http://en.wikipedia.org/wiki/SAT

"How well does the SAT I predict first-year college grades? The College Board and ETS conduct periodic studies of the SAT I. This usually involves examining the relationship between test scores and first-year college grades, generally expressed as the correlation coefficient (or r value). The College Board's Handbook for the SAT Program 2000-2001 claims the SAT-V and SAT-M have a correlation of .47 and .48, respectively, with freshman GPA (FGPA). This number is deceptive, however. To determine how much of the difference in first-year grades between students the SAT I really predicts, the correlation coefficient must be multiplied by itself. The result, called r squared, describes the difference (or variation) among college freshman grades. Thus, the predictive ability (or r squared) of the SAT I is just .22, meaning the test explains only 22% of the variation in freshman grades. With a correlation of .54, high school grades alone do a better job, explaining almost 30% of the variance in first-year college performance."

http://www.fairtest.org/facts/satvalidity.html

I took a look at your source, their numbers actually seem to imply the SAT is very good.

They mention that a 100 point increase on the SAT corresponds to a 0.1 boost on college GPA. Assume a linear relation: this means that a 1500 SAT student might expect a 3.0 GPA, while a 1000 SAT student might expect a 2.5 GPA. That's actually a great predictor.

Then they mention other studies of SAT scores within a fixed college. This is deceptive. A typical college has students from a narrow SAT range (say 1200-1400). By the above numbers, one expects that SAT predicts only 0.1 GPA above/below the mean (within the college). However, it also predicts that if the school were to ignore SAT and admit a cohort with SAT's of 800, then those students would underperform by half a letter grade.

They don't control for the college you go to?

Well, realistically I'm not sure if it would make a difference since GPA is such a tenuous concept to begin with. To quote Dressel, "A grade can be regarded only as an inadequate report of an inaccurate judgment by a biased and variable judge of the extent to which a student has attained an undefined level of mastery of an unknown proportion of an indefinite amount of material." This quote is actually from 1956; today it would be inaccurate since most classes factor some combination of attendance, homework, and participation into the grade. (To get GPA you just average all of those together using an arbitrary weighting scheme.) That's why (IIRC) GPA only accounts for about 3% of expected future earnings.

If you really wanted to figure out the value of the SAT you would have to use a much more robust measure of cognitive development than freshman GPA. However, it doesn't look like anyone is going to undertake such a massive project anytime soon. Incidentally, Alfie Kohn has some really good stuff to say about grades in both Punished By Rewards and also in What Does It Mean To Be Well Educated?

Also, I should have mentioned above that there are some meta-studies that find that degree of validity depends on the person's race, and that if you take the person's race into account the test can be useful. I have multiple objections to this though, both practical and theoretical.

Political correctness has a way of distorting reality for many people :)

Actually, it's more likely that political correctness creates a chasm between what people say and what they really think.

Reply on news.ycombinator.com