[bromang]

It cannot be coached very easily. See http://nepc.colorado.edu/files/Briggs_Theeffectofadmissionst....

"Does test preparation help improve student performance on the SAT and ACT? For students that have taken the test before and would like to boost their scores, coaching seems to help, but by a rather small amount. After controlling for group differences, the average coaching boost on the math section of the SAT is 14 to 15 points. The boost is smaller on the verbal section of the test, just 6 to 8 points. The combined effect of coaching on the SAT for the NELS sample is about 20 points."

[Steko]

"It cannot be coached very easily."

(1) This is not a universal conclusion.

(2) Many forms of "coaching" are lumped together here. In fact some may only add 30 pts or less while others add over 100.

(3) Controlling for self-selection is self-defeating here since poor black/hispanic/native american kids don't have the same opportunity to self select into say private schools with test prep programs.

(4) Taking post PSAT gains ignores coaching received prior to this.

(5) This only measures indirect coaching. The effects of a superior school itself could be large.

[bromang]

The effect "could be large". Do you have any data to support this?

Some forms of coaching "add over 100". Do you have data to support this?

Poor black/hispanic kids don't have test prep programs in school. So they are unable to get privately provided test prep or have no incentive to do so, and therefore receive a smaller amount of test prep than other racial groups. Do you have any data to support this?

The effects of a superior school "could be large". Do you have any data to support this?

You also say that you learned a lot from black and hispanic pupils. Would you have learned less from white pupils?

[Steko]

Do you really contest that private schools have better outcomes on the SAT? Or that poor kids have less test prep? Maybe you should do some basic googling on the subject before you start tossing around strident conclusions.

Having a worthwhile discussion requires a basic standard of reasonableness. Some of the perfectly reasonable claims I made could have also benefited from citations, sure. OTOH you've given me at least 5 data points that say you've just decided to be a pedantic troll about this topic. Good luck with that.