"As for the actual 'substance' of the LSAT, there isn't any," writes Pforzheimer House pre-law adviser Gene Koo in an e-mail message. "It's not like the MCAT--a lot of it involves reasoning and logic, and that's something that's hard to teach."

And the MCAT's length can be daunting. It is twice as long as the LSAT, lasting almost six hours--so long, students say, that practice is a must in order to build up endurance.

"The test is not so much a test of knowledge but a test of stamina," Kiprilov says. "They really numb you up with all those exercises and all those full-length exams that you have no choice but to let go of the stress."

For both tests, students say prep courses help them hunker down and study in the face of other distractions.

"On your own it's very difficult to say, 'I'm going to block out this entire section, and I'm going to time myself,'" says pre-med Lucy Marquez '01. "I find that if I do it myself, I do two sections and I get tired and say, 'I'm going home.'"

And studying does require major time commitments. Kristin L. Keon '01, who is enrolled in a Kaplan MCAT course, estimates that she has spent more than 15 hours a week preparing for the last two months.

Keon admits that the course environment generates stress but says that can be positive.