“Everyone and their mother takes the test in September,” a student recently told me. “I think I’m gonna sit that one out.” Why, I asked? Is it all the mothers? He looked confused. No, his mother wasn’t actually taking the test with him (duh!), but the September administration is so popular that he was afraid the curve would be much tougher. That, and all the test-centers in New York were already booked up, so he’d have to drive up to Connecticut (Canada?), and you don’t do that unless you have a pony or have a morbid curiosity about poutine.
Fine, I said. All valid points, except for one: it does not matter who else takes the test in September. Let me explain:
Contrary to popular belief, the LSAT is not graded on a curve, at least not in the traditional sense of the word. In a typical college (or law school) class, bell curving is designed to yield a pre-determined distribution of grades among the students in that class. If your Con Law final is curved to a B+, then half the class will receive a grade of B+ or higher, and the other half – B+ or lower. The LSAT scale works a bit differently. Most students assume that the test is curved based on how everyone else did that day, and conclude that a 173 on the September 2014 LSAT means they did better than 99% of the test-takers who took the September 2014 LSAT. But what if the average test-taker who chooses to take the LSAT in September is academically stronger than, say, the one who takes it in February? If the test were curved based on how everyone else did that day, then your score would depend – at least in part – on the composition of students who chose to take that particular administration. The folks at the LSAC are smart enough to figure this out. Their answer? Test-equating:
“The equating process assures that a particular LSAT scaled score reflects the same level of ability regardless of the ability level of others who tested on the same day or any slight differences in difficulty between different forms of the test. That is, the equating process assures that LSAT scores are comparable, regardless of the administration at which they are earned.” http://www.lsac.org
To put it bluntly: you can’t “game the system” by avoiding certain administrations, because the conversion scale for each administration is set ahead of time, using test data from the last three years, not from any individual LSAT. Test-makers pre-test each question in order to determine its difficulty, logical validity, possible inconsistencies, the presence of misleading information, etc. Then, each fully assembled test section is administered on one or more separate occasions (as the much reviled “experimental section”) for the purpose of pre-equating. As a result, test-makers know precisely how difficult the exam they are about to administer is, and set the conversion chart accordingly. Using the three-year pool of information provides LSAC with a stable and accurate percentile for each score. Since percentiles are not calculated on a per test basis, each test taker does not compete against the other students taking the same LSAT. Instead, he or she competes against the students from the three previous years.
So, even if all PowerScore instructors decided to have an LSAT face-off (because that’s just how we roll), we won’t skew the curve.
But your mother might.