They did not measured whether it is possible to prepare for SAT. They measured whether commercial courses boost your score. The comparison is not between student who does no additional work for SAT and the one who study a lot. The comparison is between student enrolled paying coach and the one who is not paying special SAT coach. The latter one can still work a lot with help of books and websites.
It does not mean you can not prepare for SAT, it just means that money spent on commercial coach are probably wasted. It says nowhere that if you skip all preparation altogether, you will get good result.
Quote: "Most studies have focused on estimating the effect of one specific type of test preparation, known as “coaching.” In this analysis, students Students have been coached if they have enrolled in a commercial preparation course not offered by their school but designed specifically for the SAT or ACT. The distinction made here is whether a test-taker has received systematic instruction over a short period of time. Preparation with books, videos and computers is excluded from the coaching definition because while the instruction may be systematic, it has no time constraint. Preparation with a tutor is excluded because while it may have a time constraint, it is difficult to tell if the instruction has been systematic."
Article conclusion focus on coached students only.
Note the time constraint in the above quote. People who take those tests seriously not only take the short course, but probably focused on the test long before the course started. At least, that is how well performing students I knew years ago behaved. The course itself might have boost their score only a little, but their preparation consisted of much more then just one course. After all, they are adults about to enter college - they are expected to be able to learn alone.
It does not mean you can not prepare for SAT, it just means that money spent on commercial coach are probably wasted. It says nowhere that if you skip all preparation altogether, you will get good result.
Quote: "Most studies have focused on estimating the effect of one specific type of test preparation, known as “coaching.” In this analysis, students Students have been coached if they have enrolled in a commercial preparation course not offered by their school but designed specifically for the SAT or ACT. The distinction made here is whether a test-taker has received systematic instruction over a short period of time. Preparation with books, videos and computers is excluded from the coaching definition because while the instruction may be systematic, it has no time constraint. Preparation with a tutor is excluded because while it may have a time constraint, it is difficult to tell if the instruction has been systematic."
Article conclusion focus on coached students only.
Note the time constraint in the above quote. People who take those tests seriously not only take the short course, but probably focused on the test long before the course started. At least, that is how well performing students I knew years ago behaved. The course itself might have boost their score only a little, but their preparation consisted of much more then just one course. After all, they are adults about to enter college - they are expected to be able to learn alone.