My daughter took the 6-week SAT prep course with Dr. Ilia Kolmagorov as the instructor. She started the course 2 weeks late, but was able to catch up on the material on her own as the course progressed. Her score on the initial SAT practice test (prior to starting the course) was 1280. Her score on the final SAT practice test (after finishing the course) was 1420. That is an improvement of 140 points over a 4-week span, which is very good. She hopes to continue making improvements with subsequent practice tests and reviewing the test taking strategies Dr. Kolmagorov taught in the course. What she liked best about the course was the thoroughness of the instructor's explanations and the test-taking strategies he taught for specific types of math problems, which allow students to save time during the actual test. From a parent's perspective, this course represented a worthwhile investment ($) based on the SAT score improvements my daughter has already made.