I had a bit of free time, so I did an SAT-ACT table.

futureEE · 01-08-2009, 02:22 AM

Alright guys, I just did my own version of the SAT-ACT conversion charts floating around. I got the offical data:
http://www.act.org/news/data/08/pdf/National2008.pdf
http://www.collegeboard.com/prod_dow...tile_ranks.pdf

And it turned out around 1.4 million students took each test, so it was really easy to compute exact percentiles and then convert.
I calculated the percent of students that score AT or below the given score, and found that every score on the ACT matched with an SAT score within 0.1 percentage point.

Here are my results:

ACTSAT--Percent of students at or below this score
36-2400-100
35-2390-99.98
34-2300-99.7
33-2250-99.3
32-2200-98.6
31-2140-97.4
30-2070-95.8
29-2000-93.7
28-1950-91.5
27-1890-88.2
26-1830-84.3
25-1780-80.4

Basically, this means if you get 32 (like I did), 98.6% of the students that took either test scored at or below 32/2200.

My results pretty much meshed with all the table floating around, but I was much more accurate in calculating the percentiles. I should note that the table in the ACT article of wikipedia is pretty far off the mark though, all the others are good.

califa · 01-08-2009, 02:38 AM

Thanks. Looks like with these percentiles I should go along with letting my daughter (who got a 29 as a sophomore and a 185 on the PSAT, both with no prep) skip the SAT and focus on retaking the ACT, this time with some prep. She doesn't want to take the ACT because math is pulling down her scores on both tests, but it counts more on the SAT.

Anyone else skipping the SAT completely?

xxJustAMomxx · 01-08-2009, 12:06 PM

I want my daughter to skip the SAT completely and just focus on the ACT, but when I tell people this, they look at me like I'm out of my mind. (We live in the Northeast). She got a 170 something on the PSAT and a 29 on her first ACT, both with virtually no prep. My older daughter studied like crazy for the SAT but never got above 1870, but got a 31 on the ACT (and was a top student, as is my younger daughter). She never even submitted her SAT score.

Is it crazy not to take the SAT, and just focus on the ACT????

hardworker · 01-08-2009, 04:08 PM

nope. im a junior and i gave up on the SAT a looooong time ago! but then again, i live in the midwest so taking the SAT is pretty much unheard of around here anyway. although I hope to apply to top schools too and im hoping ACT vs. SAT doesnt matter much becuse ive been getting some mixed responses around here. :/ comments?

xcfan · 01-08-2009, 04:50 PM

Interesting comparison. There is actually a science to developing concordance tables. This approach -- matching percentiles -- is sometimes used as a short cut, but is considered less statistically reliable. That is why the SAT/ACT folks developed a specific concordance table. The results in the middle dont vary much, but at the extremes they do. For example, your table shows an ACT 35 as equal to a SAT 2390. But the "official" concordances would say either (1) an ACT 35 is a SAT CR/M 1560 and you need to add writing separately, or (2) an ACT 35 "represents" a SAT 2330. The SAT website only provides the two step concordance. The ACT website provides both a two step concordance and a one step conversion.

tsh1226 · 01-08-2009, 05:41 PM

ACT-SAT Concordance

haha this is the official CB and ACT score concordance table. Good work, but this is legit

califa · 01-09-2009, 12:40 AM

The official table tells me the same thing. D's 185 on the PSAT was 66 CR, 66W, 53 math, with a projected SAT CR + M of 1190, which equals a 26 on the ACT. So her ACT is still better than the SAT.

JustaMom and Hardworker - thanks for sharing about not taking the SAT. I'm going to let D skip it, since she doesn't want to do any test prep and it seems to make more sense to focus on just one test. Another thing: if the college requires SAT subject tests, even if we choose not to send SATs, they will see those scores with the subject tests, which would not be a good thing if she doesn't do as well on the SAT as ACT.

All schools take both, so I don't see any problems in skipping the SAT. I was just wondering because the guidance counselor suggested she take the SAT anyway, but we live in SAT land. Not too many take the ACT here, but it's getting more popular and many kids take both.

yawn · 01-09-2009, 12:55 AM

Hm, so I guess I'm at 93.7 for the ACT and just under 98.6 for the SAT. So if this was something you could "average", about 95.5. Meh, not bad.

But, as you can see from my scores, often times a student will do significantly better on one test than the other. Then again, I got the SAT score on my second try and I only took the ACT once. I s'ppose my two highest scores would level out if I took the ACT again. Oh well, wutevz.

rjacob · 01-09-2009, 02:05 PM

This scale is pretty darn accurate. The scale made by the ACT and College board seems inaccurate, IMO.

worried mom · 01-09-2009, 08:23 PM

We live in the northeast also and my daughter, who is a senior, only took the ACT and the PSAT. So far she has gotten into Boston College, Villanova & Fordham EA and Univ. of Pittsburgh (full tuition scholarship).
The colleges are fine with no SAT but the guidance counselors act as though you are on drugs.

futureEE · 01-10-2009, 02:05 AM

I should add that my chart does obviously use the SAT2400 scale, meaning that the writing score is lumped in there on the SAT, while not the ACT. It still should be fairly accurate though, as I can't imagine a huge difference in writing scores versus the others.

The official chart uses the 1600 scale, and then a seperate writing.

However I should point out that for a truely accurate conversion, you really need to throw out the ACT science scores...

My percentiles are as accurate as you'll find though, they are rounded by at most 0.05%.

xxJustAMomxx · 01-10-2009, 08:49 AM

worried mom...I know what you mean! My oldest daughter did so much better on the ACT that she didn't even submit her SATs. Based on the PSAT and her first ACT score, my younger daughter seems to be in the same place. So I thought that it would make the most sense for her to concentrate on just the ACT, but everyone thinks we're crazy, and that's starting to worry my daughter. Congrats on your daughter's acceptances!

xcfan · 01-10-2009, 09:05 AM

Worried Mom and Just a Mom,

Same situation with both of my older kids -- stronger ACT than SAT. Two thoughts. First, dont worry about the SAT and just focus on the ACT. Every school accepts the ACT now. The people (including guidance counselors) who tell you that you are crazy and basing that judgement on out of date information.

Second, if you take the analysis one level further, look at the "common data" set for any school to which your child is applying. This will show you what percent of the matriculating students submitted ACT scores. Most schools in the midwest (eg U Chicago, Carleton, etc) will have almost 50% of the students submitting ACT scores, so those school obviously are completely comfortable with ACT scores. Even schools on the East Coast (eg Yale, Amherst, etc) have 20% or so of student submitting ACT scores. Occasionally you will find a school (eg Haverford) that just does not seem to have very many ACT scores submitted. But at any school that still requires the SAT II tests even with the ACT (like Haverford), they probably are using the SAT II scores to overcome any residual uncertainty or unfamilarity they have with the ACT alone. Bottom line is still -- dont worry, the ACT alone is fine.

dychang · 01-10-2009, 09:26 AM

haha... I should be getting 28~29 on ACT based on my SAT (CR+M) score, but I don't!!! I guess some people are better at a certain test.......?

futureEE · 01-10-2009, 04:01 PM

Dychang, thats exactly it. I'm supposed to be getting 25 from my SAT scores, and I get 32.

Of course I am retaking SAT in two weeks...