Carl has taught, literally, thousands of students to succeed on the GRE, and thousands more the ACT, SAT, LSAT, and GMAT, over a career spanning over two decades in the test preparation world. Originally an academic, he holds advanced degrees from Yale, the University of Glasgow, and the University of Georgia, and since leaving academia he has taught, tutored, and written content for Magoosh, Kaplan, Harvard Prep, SuccessPrep, Parliament Tutors, Varsity Tutors, and many other companies, and has since founded his own company, Ivory Tower Tutoring. He was also, for many years, the chief writer for Barron''s GMAT product line.