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.
Some time ago, I wrote about a flawed question, in The Official SAT Study Guide from the College Board. In trying to understand the thinking of the question writer, I reviewed the official explanations to the test that are available on the College Board's website through its online course.