Many colleges (including my own) are tightening their requirements for accepting Advanced Placement credit. This Washington Post piece has details--and sides with AP.

Although I'm skeptical (especially for highly-selective colleges), Jay Mathews may well be right that AP courses provide as good a preparation for upper-level college courses as introductory college courses. However, I take issue with this paragraph:

That was one small study. I found another selective college has done another small study that reaches a different conclusion. At Claremont McKenna College in Claremont, Calif., students who skipped introductory calculus by getting a grade of 4 or 5 in AP calculus AB or BC had an average grade of 11 out of 12 points in its follow-up calculus course. This was better than the average grade of 9.51 for all students in that follow-up course. The same thing happened in Spanish. Students who skipped the equivalent course at Claremont McKenna by scoring 4 or 5 in AP Spanish had an average grade of 11.29 in the college's follow-up course, which was higher than the average grade of 10.68 for all students in that course.

One of the things that Mr. Mathews might have learned in one of my introductory college courses is the notion of selection bias. It is possible--I'd say probable--that the Claremont students who took AP courses would have also done better in upper-level classes even if they'd taken introductory college classes instead of AP.