In part one, I made the rather unoriginal claim that most commercial test-prep material sucks, and suggested that one major reason it's so bad is that doing good work is hard and that there is insufficient financial incentive for publishers to put resources into doing it right.
Here's the lede:
The revamped SAT, expanded three years ago to include a writing test, predicts college success no better than the old test, and not quite as well as a student’s high school grades
(Part 1, Part 3)
The instructions for the writing sections of the the SAT ask the test taker to use the conventions of "standard written English" in finding correct answers. But as I noted in part 1 of this article, the public specifications as to what that means, are vague.