ACT vs. SAT?
Many parents ask me which exam is better for their son or daughter: the SAT or ACT.
Unfortunately, there is no hard evidence that any “type” of student scores higher on either the SAT or ACT. This of course flies in the face of the oft repeated factoid that the SAT favors analytical thinkers while the ACT favors holistic thinkers.
So what should you do?
The short answer is you should take both exams to determine which suits you. This is what The Princeton Review and other reputable sources recommend. The long answer is that even this may be misleading.

What College Board and ACT don’t advertise is that both tests experience considerable score drift. That is, the same student with the same knowledge will score significantly higher or lower on different days. On the Old SAT, we saw score drift as great as 150 points. Anecdotally, I’ve seen concordant drift on the ACT and Redesigned SAT. This means that doing significantly better on either SAT or ACT does not prove the test suits you.
I would also caution against student testimony as a determining factor. In the five years I have taught SAT and ACT full time, many students have reported feeling that they did very poorly only to receive their best score. And yes, unfortunately, many students have told me they felt very confident about their scores only to underperform.
As I stress to my students, “feeling” on these kinds of tests is not a reliable predictor of results. Both SAT and ACT are specifically structured to hedge feeling and test knowledge. So whether you feel good or bad, it is unlikely your score had anything to do with it.

All this means students should not only take both exams but take both exams repeatedly. If you observe a higher than average concordant score over 2-3 exams, then you know that exam suits you. Of course, most students, understandably, have neither the time nor energy to take six, 4-hour exams merely to determine which exam is better “for them.”
Which brings me to the method I recommend to parents and students when they ask the proverbial question: But what about ACT? Isn’t that better for non-Math kids?
Prep for the SAT because it is easier to prep for. There are more materials, more teachers and, structurally, the test probably lends itself to prep better than does the ACT. Take the ACT once just to see if there’s a discrepancy in score. Usually there isn’t, but it’s worth trying.