In their controversial study, College Board researchers compared the score gains of two groups of students who took the SAT twice. The Board found that taking a commercial course helped but not a lot. The scores of students who didn't take a test-prep course rose by an average of 43 points. Pupils of Kaplan Educational Centers and the Princeton Review increased only 19 to 42 points more, on average. Students of less well-known coaching companies exhibited an average rise of 13 to 19 points above their uncoached peers.
Critics say the study is too flawed to assess accurately the effect of test-prep classes.
First, only about 60 percent of the 6,700 students the College Board surveyed chose to respond to the Board's questionnaire. Further, the College Board's sample of uncoached students actually scored much higher than uncoached students did in previous studies, says Robins, who speculates that only the highest-scoring uncoached students answered the Board's questionnaire. Commercial test-prep courses undoubtedly have helped some students achieve score gains. For instance, Andrew Leeds, now a senior at Stanford , says his score jumped 270 points after he took a Kaplan class. College Board officials don't deny that preparing for the SAT can help raise scores.